From 049748b9f426b9593b972f0d79825927c70d581f Mon Sep 17 00:00:00 2001
From: Lincoln Stein <lincoln.stein@gmail.com>
Date: Thu, 6 Aug 2026 18:39:24 -0400
Subject: [PATCH 1/2] fix(ui): don't strand the viewer under the video progress
 overlay

During a video render, the progress-preview overlay swallowed every
gallery thumbnail click: the selection changed underneath, but the
opaque overlay stayed on top, so nothing visibly happened until a tab
switch remounted the viewer. Three causes, three fixes:

- CurrentVideoPreview never implemented the temporary reveal that
  CurrentImagePreview got in #9217. Port it: clicking a thumbnail
  mid-render now lifts the overlay for 2 s so the click visibly lands,
  then the live preview returns. An actively-playing video is never
  re-covered (audio would keep running under an opaque overlay with
  unreachable controls); the overlay returns when the player closes.

- The reveal's previous-item tracking was per-component, so any click
  that switched media type (image <-> video swaps the mounted preview
  component) reset it and the reveal was swallowed. The ref now lives
  in the shared ImageViewerContext; the image side is careful not to
  null it while a preload is still pending (adversarial-review finding:
  the mount run would otherwise erase the previous-video fact and kill
  the video->image reveal).

- After completion, the "preview resolves into the final media" clear
  only fired from the final media's load callback. On a slow connection
  that lags far behind completion, and an errored <video> never fires
  it - stranding the overlay permanently. The video error handler now
  clears a pending resolve, and a 10 s failsafe in the context drops
  the illusion rather than strand the overlay.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 .../ImageViewer/CurrentImagePreview.tsx       | 23 ++++--
 .../ImageViewer/CurrentVideoPreview.test.ts   | 22 ++++++
 .../ImageViewer/CurrentVideoPreview.tsx       | 74 ++++++++++++++++++-
 .../components/ImageViewer/context.tsx        | 44 ++++++++++-
 4 files changed, 150 insertions(+), 13 deletions(-)

diff --git a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentImagePreview.tsx b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentImagePreview.tsx
index 1978a7fc1ab..043551efdf3 100644
--- a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentImagePreview.tsx
+++ b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentImagePreview.tsx
@@ -19,7 +19,7 @@ import { AnimatePresence, motion } from 'framer-motion';
 import { memo, useCallback, useEffect, useRef, useState } from 'react';
 import type { ImageDTO } from 'services/api/types';
 
-import { useImageViewerContext } from './context';
+import { SELECTED_ITEM_REVEAL_DURATION_MS, useImageViewerContext } from './context';
 import { NoContentForViewer } from './NoContentForViewer';
 import { ProgressImage } from './ProgressImage2';
 import { ProgressImageTiles } from './ProgressImageTiles';
@@ -38,6 +38,7 @@ export const CurrentImagePreview = memo(({ imageDTO }: { imageDTO: ImageDTO | nu
     $activeProgressData,
     $isProgressImageResolving,
     $isTemporarilyShowingSelectedImage,
+    lastRenderedItemNameRef,
   } = useImageViewerContext();
   const progressEvent = useStore($progressEvent);
   const progressImage = useStore($progressImage);
@@ -45,7 +46,6 @@ export const CurrentImagePreview = memo(({ imageDTO }: { imageDTO: ImageDTO | nu
   const isProgressImageResolving = useStore($isProgressImageResolving);
   const isTemporarilyShowingSelectedImage = useStore($isTemporarilyShowingSelectedImage);
   const [imageToRender, setImageToRender] = useState<ImageDTO | null>(null);
-  const previousRenderedImageNameRef = useRef<string | null>(null);
   const selectedImageRevealTimeoutId = useRef(0);
 
   useEffect(() => {
@@ -93,8 +93,16 @@ export const CurrentImagePreview = memo(({ imageDTO }: { imageDTO: ImageDTO | nu
 
   useEffect(() => {
     const renderedImageName = imageToRender?.image_name ?? null;
-    const previousRenderedImageName = previousRenderedImageNameRef.current;
-    previousRenderedImageNameRef.current = renderedImageName;
+    // The previous-item ref is shared with CurrentVideoPreview (via the viewer context) so a click
+    // that switches media type still reads as a selection change here. While a selection exists
+    // but its preload hasn't landed yet (renderedImageName still null on the mount run after a
+    // video -> image swap), the ref must NOT be overwritten — nulling it here would erase the
+    // "previous item was the video" fact and swallow the reveal this run's successor would fire.
+    // A genuinely empty selection does reset it, preserving the no-reveal-on-first-selection rule.
+    const previousRenderedItemName = lastRenderedItemNameRef.current;
+    if (renderedImageName !== null || !selectedImageName) {
+      lastRenderedItemNameRef.current = renderedImageName;
+    }
 
     window.clearTimeout(selectedImageRevealTimeoutId.current);
 
@@ -109,14 +117,14 @@ export const CurrentImagePreview = memo(({ imageDTO }: { imageDTO: ImageDTO | nu
       return;
     }
 
-    if (previousRenderedImageName === null || previousRenderedImageName === renderedImageName) {
+    if (previousRenderedItemName === null || previousRenderedItemName === renderedImageName) {
       return;
     }
 
     $isTemporarilyShowingSelectedImage.set(true);
     selectedImageRevealTimeoutId.current = window.setTimeout(() => {
       $isTemporarilyShowingSelectedImage.set(false);
-    }, SELECTED_IMAGE_REVEAL_DURATION_MS);
+    }, SELECTED_ITEM_REVEAL_DURATION_MS);
 
     return () => {
       window.clearTimeout(selectedImageRevealTimeoutId.current);
@@ -126,6 +134,7 @@ export const CurrentImagePreview = memo(({ imageDTO }: { imageDTO: ImageDTO | nu
     hasProgressImage,
     imageToRender?.image_name,
     isProgressImageResolving,
+    lastRenderedItemNameRef,
     selectedImageName,
     shouldShowProgressInViewer,
   ]);
@@ -271,5 +280,3 @@ const exit: AnimationProps['exit'] = {
   opacity: 0,
   transition: { duration: 0.07 },
 };
-
-const SELECTED_IMAGE_REVEAL_DURATION_MS = 2000;
diff --git a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts
index 9a22e8cc321..cb9bd2c4f40 100644
--- a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts
+++ b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts
@@ -11,3 +11,25 @@ describe('CurrentVideoPreview playback errors', () => {
     expect(source).toContain('onError={handleVideoError}');
   });
 });
+
+describe('CurrentVideoPreview progress overlay', () => {
+  const source = readFileSync(fileURLToPath(new URL('./CurrentVideoPreview.tsx', import.meta.url)), 'utf8');
+
+  it('lifts the overlay during the temporary reveal so mid-render thumbnail clicks visibly land', () => {
+    // The overlay must consult the shared reveal atom (and never re-cover an actively-playing
+    // video) — an unconditional overlay swallows every gallery click for the whole render.
+    expect(source).toMatch(
+      /withProgress =\s+shouldShowProgressInViewer && hasProgressImage && !isTemporarilyShowingSelectedImage && !isPlaying/
+    );
+    expect(source).toContain('SELECTED_ITEM_REVEAL_DURATION_MS');
+    // The previous-item ref must be the shared one from the viewer context, so image -> video
+    // clicks still read as a selection change after the preview component swaps.
+    expect(source).toContain('lastRenderedItemNameRef.current = videoName');
+  });
+
+  it('clears a pending post-render overlay when the video element errors', () => {
+    // onLoadedMetadata normally clears the resolve state; an errored element never fires it.
+    const errorHandler = source.slice(source.indexOf('const handleVideoError'), source.indexOf('const handlePlay'));
+    expect(errorHandler).toContain('onLoadImage()');
+  });
+});
diff --git a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx
index 9329a7173c7..893bdf69cec 100644
--- a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx
+++ b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx
@@ -30,7 +30,7 @@ import { useTranslation } from 'react-i18next';
 import { PiArrowSquareOutBold, PiCopyBold, PiDownloadSimpleBold, PiTrashSimpleBold, PiXBold } from 'react-icons/pi';
 import type { VideoDTO } from 'services/api/types';
 
-import { useImageViewerContext } from './context';
+import { SELECTED_ITEM_REVEAL_DURATION_MS, useImageViewerContext } from './context';
 import { NoContentForViewer } from './NoContentForViewer';
 import { ProgressImage } from './ProgressImage2';
 import { ProgressIndicator } from './ProgressIndicator2';
@@ -57,6 +57,8 @@ type Props = {
  * appear on top of the previously-loaded video. Without this, a freshly generated render's
  * progress images had nowhere to display whenever a video was the last-selected gallery
  * item (and the user only saw the static first-frame still until the new video finished).
+ * Also mirrors its temporary reveal: clicking a gallery thumbnail mid-render lifts the
+ * overlay briefly so the click visibly lands, then the live preview returns.
  */
 export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
   const videoUrl = useMediaUrl(videoDTO?.video_url);
@@ -71,17 +73,77 @@ export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
   const deleteVideoModal = useDeleteVideoModalApi();
   const { downloadItem } = useDownloadItem();
   const clipboard = useClipboard();
-  const { $progressEvent, $progressImage, onLoadImage } = useImageViewerContext();
+  const {
+    $progressEvent,
+    $progressImage,
+    $isProgressImageResolving,
+    $isTemporarilyShowingSelectedImage,
+    lastRenderedItemNameRef,
+    onLoadImage,
+  } = useImageViewerContext();
   const progressEvent = useStore($progressEvent);
   const progressImage = useStore($progressImage);
-  const withProgress = shouldShowProgressInViewer && progressImage !== null;
+  const isProgressImageResolving = useStore($isProgressImageResolving);
+  const isTemporarilyShowingSelectedImage = useStore($isTemporarilyShowingSelectedImage);
+  const hasProgressImage = progressImage !== null;
+  // `!isPlaying`: a reveal exposes the play button, and an explicit play is a stronger signal than
+  // the click that triggered the reveal — never re-cover an actively-playing video with the opaque
+  // overlay (its audio would keep running underneath, with the controls unreachable). The overlay
+  // returns when the user closes the player.
+  const withProgress =
+    shouldShowProgressInViewer && hasProgressImage && !isTemporarilyShowingSelectedImage && !isPlaying;
   const { goToPreviousImage, goToNextImage, isFetching } = useNextPrevItemNavigation();
+  const selectedVideoRevealTimeoutId = useRef(0);
 
   // Whenever the selected video changes, drop back to the idle still + play overlay.
   useEffect(() => {
     setIsPlaying(false);
   }, [videoName]);
 
+  // Mid-generation gallery clicks: mirror CurrentImagePreview's temporary reveal. Without this,
+  // the opaque progress overlay swallows every video-thumbnail click for the whole render — the
+  // selection changes underneath, but nothing visibly happens. Unlike the image path there is no
+  // preload step: the <video> renders immediately (first frame paints when metadata arrives), so
+  // the reveal is keyed directly off the selected video name. The previous-item ref is shared with
+  // CurrentImagePreview so an image -> video click still reads as a selection change.
+  useEffect(() => {
+    const previousRenderedItemName = lastRenderedItemNameRef.current;
+    lastRenderedItemNameRef.current = videoName;
+
+    window.clearTimeout(selectedVideoRevealTimeoutId.current);
+
+    if (!shouldShowProgressInViewer || !hasProgressImage || isProgressImageResolving || !videoName) {
+      $isTemporarilyShowingSelectedImage.set(false);
+      return;
+    }
+
+    if (previousRenderedItemName === null || previousRenderedItemName === videoName) {
+      return;
+    }
+
+    $isTemporarilyShowingSelectedImage.set(true);
+    selectedVideoRevealTimeoutId.current = window.setTimeout(() => {
+      $isTemporarilyShowingSelectedImage.set(false);
+    }, SELECTED_ITEM_REVEAL_DURATION_MS);
+
+    return () => {
+      window.clearTimeout(selectedVideoRevealTimeoutId.current);
+    };
+  }, [
+    $isTemporarilyShowingSelectedImage,
+    hasProgressImage,
+    isProgressImageResolving,
+    lastRenderedItemNameRef,
+    shouldShowProgressInViewer,
+    videoName,
+  ]);
+
+  useEffect(() => {
+    return () => {
+      $isTemporarilyShowingSelectedImage.set(false);
+    };
+  }, [$isTemporarilyShowingSelectedImage]);
+
   // Register the viewer's <video> as a drag source so users can drag the currently-displayed
   // video onto node fields (e.g. a Video Primitive's "Starting Video" input) directly from
   // the viewer, just like they can from the gallery thumbnail. Mirrors GalleryVideoItem's
@@ -125,13 +187,17 @@ export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
     if (isMediaCookieSelfHealPending()) {
       return;
     }
+    // A genuinely errored element will never fire onLoadedMetadata, which is what normally clears
+    // a pending post-render progress overlay — clear it here or it strands over the viewer.
+    // (onLoadImage is a no-op unless a resolve is actually pending.)
+    onLoadImage();
     toast({
       id: 'VIDEO_PLAYBACK_FAILED',
       status: 'error',
       title: t('toast.videoPlaybackFailed'),
       description: t('toast.videoPlaybackFailedDesc'),
     });
-  }, [t]);
+  }, [onLoadImage, t]);
 
   const handlePlay = useCallback(() => {
     setIsPlaying(true);
diff --git a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/context.tsx b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/context.tsx
index 74fb418761f..9121472bed3 100644
--- a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/context.tsx
+++ b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/context.tsx
@@ -5,7 +5,7 @@ import { selectAutoSwitch } from 'features/gallery/store/gallerySelectors';
 import type { ProgressImage as ProgressImageType } from 'features/nodes/types/common';
 import { LRUCache } from 'lru-cache';
 import { type Atom, atom, computed, map, type MapStore, type WritableAtom } from 'nanostores';
-import type { PropsWithChildren } from 'react';
+import type { MutableRefObject, PropsWithChildren } from 'react';
 import { createContext, memo, useCallback, useContext, useEffect, useMemo, useRef, useState } from 'react';
 import type { S } from 'services/api/types';
 import { getEventScope } from 'services/events/eventScope';
@@ -33,9 +33,23 @@ type ImageViewerContextValue = {
   $activeProgressData: Atom<ViewerProgressDatum[]>;
   $isProgressImageResolving: Atom<boolean>;
   $isTemporarilyShowingSelectedImage: WritableAtom<boolean>;
+  /** Name of the item most recently rendered by either preview component (image or video). Shared
+   * across the two components so a click that switches media type (image -> video or back) still
+   * reads as a selection change to the temporary-reveal logic — a per-component ref resets on the
+   * swap and would silently swallow the first reveal after every type switch. */
+  lastRenderedItemNameRef: MutableRefObject<string | null>;
   onLoadImage: () => void;
 };
 
+/** How long a mid-generation gallery click shows the clicked item before the live preview returns. */
+export const SELECTED_ITEM_REVEAL_DURATION_MS = 2000;
+
+/** Upper bound on the post-completion "progress preview resolves into the final media" illusion.
+ * The clear normally fires from the final image's onLoad / the final video's onLoadedMetadata, but
+ * on a slow connection that load can lag far behind completion — and if the media element errors,
+ * it never fires at all. Past this deadline we drop the illusion rather than strand the overlay. */
+const RESOLVE_FAILSAFE_MS = 10_000;
+
 const ImageViewerContext = createContext<ImageViewerContextValue | null>(null);
 
 const log = logger('events');
@@ -59,6 +73,8 @@ export const ImageViewerContextProvider = memo((props: PropsWithChildren) => {
   const $isProgressImageResolving = useState(() => atom(false))[0];
   const $isTemporarilyShowingSelectedImage = useState(() => atom(false))[0];
   const shouldClearProgressImageOnLoadRef = useRef(false);
+  const lastRenderedItemNameRef = useRef<string | null>(null);
+  const resolveFailsafeTimeoutRef = useRef(0);
   // We can have race conditions where we receive a progress event for a queue item that has already finished. Easiest
   // way to handle this is to keep track of finished queue items in a cache and ignore progress events for those.
   const [finishedQueueItemIds] = useState(() => new LRUCache<number, boolean>({ max: 200 }));
@@ -81,6 +97,8 @@ export const ImageViewerContextProvider = memo((props: PropsWithChildren) => {
         );
         return;
       }
+      // A new render owns the display now; a pending resolve (and its failsafe) is moot.
+      window.clearTimeout(resolveFailsafeTimeoutRef.current);
       shouldClearProgressImageOnLoadRef.current = false;
       $isProgressImageResolving.set(false);
       $progressEvent.set(data);
@@ -153,6 +171,7 @@ export const ImageViewerContextProvider = memo((props: PropsWithChildren) => {
           // will be stuck on the viewer.
           (data.origin === 'canvas' && data.destination !== 'canvas')
         ) {
+          window.clearTimeout(resolveFailsafeTimeoutRef.current);
           shouldClearProgressImageOnLoadRef.current = false;
           $isProgressImageResolving.set(false);
           $progressEvent.set(null);
@@ -160,6 +179,20 @@ export const ImageViewerContextProvider = memo((props: PropsWithChildren) => {
         } else {
           shouldClearProgressImageOnLoadRef.current = true;
           $isProgressImageResolving.set(true);
+          // Failsafe: onLoadImage normally performs this clear when the final media loads, but on
+          // a slow connection that can lag far behind completion, and an errored media element
+          // never fires it — stranding the opaque overlay until a tab switch remounts this
+          // provider. Past the deadline, drop the resolve illusion and clear directly.
+          window.clearTimeout(resolveFailsafeTimeoutRef.current);
+          resolveFailsafeTimeoutRef.current = window.setTimeout(() => {
+            if (!shouldClearProgressImageOnLoadRef.current) {
+              return;
+            }
+            shouldClearProgressImageOnLoadRef.current = false;
+            $isProgressImageResolving.set(false);
+            $progressEvent.set(null);
+            $progressImage.set(null);
+          }, RESOLVE_FAILSAFE_MS);
         }
       }
     };
@@ -185,12 +218,20 @@ export const ImageViewerContextProvider = memo((props: PropsWithChildren) => {
       return;
     }
 
+    window.clearTimeout(resolveFailsafeTimeoutRef.current);
     shouldClearProgressImageOnLoadRef.current = false;
     $isProgressImageResolving.set(false);
     $progressEvent.set(null);
     $progressImage.set(null);
   }, [$isProgressImageResolving, $progressEvent, $progressImage]);
 
+  useEffect(() => {
+    const timeoutRef = resolveFailsafeTimeoutRef;
+    return () => {
+      window.clearTimeout(timeoutRef.current);
+    };
+  }, []);
+
   const value = useMemo(
     () => ({
       $progressEvent,
@@ -200,6 +241,7 @@ export const ImageViewerContextProvider = memo((props: PropsWithChildren) => {
       $activeProgressData,
       $isProgressImageResolving,
       $isTemporarilyShowingSelectedImage,
+      lastRenderedItemNameRef,
       onLoadImage,
     }),
     [

From 80483c85d8418d8720243b0538bc65f5be75e906 Mon Sep 17 00:00:00 2001
From: Lincoln Stein <lincoln.stein@gmail.com>
Date: Thu, 6 Aug 2026 20:07:55 -0400
Subject: [PATCH 2/2] fix(ui): tile concurrent session previews in the video
 viewer (multi-GPU)

CurrentImagePreview tiles per-session previews when more than one
render runs concurrently; CurrentVideoPreview only ever rendered the
single shared latest preview, so parallel sessions overwrote each
other's frames in place. Port the ProgressImageTiles branch, mirroring
the image viewer exactly ($activeProgressData is already tracked
per-session in the shared context).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 .../ImageViewer/CurrentVideoPreview.test.ts    |  7 +++++++
 .../ImageViewer/CurrentVideoPreview.tsx        | 18 +++++++++++++++---
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts
index cb9bd2c4f40..945fd1702c1 100644
--- a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts
+++ b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.test.ts
@@ -27,6 +27,13 @@ describe('CurrentVideoPreview progress overlay', () => {
     expect(source).toContain('lastRenderedItemNameRef.current = videoName');
   });
 
+  it('tiles concurrent sessions instead of letting them overwrite each other (multi-GPU)', () => {
+    // CurrentImagePreview tiles per-session previews when several renders run at once; the video
+    // overlay must do the same or the sessions fight over the single full-size preview slot.
+    expect(source).toMatch(/withTiledProgress = withProgress && activeProgressData\.length > 1/);
+    expect(source).toContain('<ProgressImageTiles data={activeProgressData} />');
+  });
+
   it('clears a pending post-render overlay when the video element errors', () => {
     // onLoadedMetadata normally clears the resolve state; an errored element never fires it.
     const errorHandler = source.slice(source.indexOf('const handleVideoError'), source.indexOf('const handlePlay'));
diff --git a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx
index 893bdf69cec..35369b91613 100644
--- a/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx
+++ b/invokeai/frontend/web/src/features/gallery/components/ImageViewer/CurrentVideoPreview.tsx
@@ -33,6 +33,7 @@ import type { VideoDTO } from 'services/api/types';
 import { SELECTED_ITEM_REVEAL_DURATION_MS, useImageViewerContext } from './context';
 import { NoContentForViewer } from './NoContentForViewer';
 import { ProgressImage } from './ProgressImage2';
+import { ProgressImageTiles } from './ProgressImageTiles';
 import { ProgressIndicator } from './ProgressIndicator2';
 import { VideoPlayButtonOverlay } from './VideoPlayButtonOverlay';
 
@@ -76,6 +77,7 @@ export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
   const {
     $progressEvent,
     $progressImage,
+    $activeProgressData,
     $isProgressImageResolving,
     $isTemporarilyShowingSelectedImage,
     lastRenderedItemNameRef,
@@ -83,6 +85,7 @@ export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
   } = useImageViewerContext();
   const progressEvent = useStore($progressEvent);
   const progressImage = useStore($progressImage);
+  const activeProgressData = useStore($activeProgressData);
   const isProgressImageResolving = useStore($isProgressImageResolving);
   const isTemporarilyShowingSelectedImage = useStore($isTemporarilyShowingSelectedImage);
   const hasProgressImage = progressImage !== null;
@@ -92,6 +95,9 @@ export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
   // returns when the user closes the player.
   const withProgress =
     shouldShowProgressInViewer && hasProgressImage && !isTemporarilyShowingSelectedImage && !isPlaying;
+  // When more than one session is generating concurrently (multi-GPU), tile their previews instead
+  // of letting the sessions overwrite each other's full-size preview. Mirrors CurrentImagePreview.
+  const withTiledProgress = withProgress && activeProgressData.length > 1;
   const { goToPreviousImage, goToNextImage, isFetching } = useNextPrevItemNavigation();
   const selectedVideoRevealTimeoutId = useRef(0);
 
@@ -421,9 +427,15 @@ export const CurrentVideoPreview = memo(({ videoDTO }: Props) => {
       )}
       {withProgress && (
         <Flex w="full" h="full" position="absolute" alignItems="center" justifyContent="center" bg="base.900">
-          <ProgressImage progressImage={progressImage} />
-          {progressEvent && (
-            <ProgressIndicator progressEvent={progressEvent} position="absolute" top={6} right={6} size={8} />
+          {withTiledProgress ? (
+            <ProgressImageTiles data={activeProgressData} />
+          ) : (
+            <>
+              <ProgressImage progressImage={progressImage} />
+              {progressEvent && (
+                <ProgressIndicator progressEvent={progressEvent} position="absolute" top={6} right={6} size={8} />
+              )}
+            </>
           )}
         </Flex>
       )}