I’ve combed everywhere but I can’t seem to even find someone with a similar problem!
It’s this list of thumbnails:
Ask Different is a question and answer site for power users of Apple hardware and software. It only takes a minute to sign up.Sign up to join this community
It’s called the Shelf and is new in iPadOS 15. It replaces the grid view of windows in previous versions that was less discoverable, requiring an additional tap on the app icon after opening.
The new multi-window shelf gives you quick access to all the open windows for an app. The shelf appears when you open an app and elegantly fades away as soon as you interact with the app. Tap one to open it or flick it away to close.
The presence of the shelf is controlled by having other open windows of the same app. If there are no other open windows, it won’t be shown automatically. Close the other open windows by sliding them up.
I searched for iPad expose since it looks similar to macOS expose.
The open windows in some apps appear as thumbnails near the bottom of the screen. When you tap a thumbnail, its contents appear in the current full-screen window.