Comment by jimrandomh
12 hours ago
The full-screen mode handling might be a clue about what went wrong: if you swipe up from a space that contains a full screen app, it has an animation where the app goes into a slot in the preview strip, but that animation doesn't make sense visually for a non-full-screen space. So, perhaps someone was implementing that animation, didn't want to implement an alternate animation for the non-fullscreen case, and decided to minimize the preview strip instead? And because this was after Steve Jobs had died, there was no one left in charge of UX to explain why that was a bad idea?
The animation for the full-screen case serves a useful purpose: drawing the eye to the window in the preview.
The non-fullscreen (desktop) case uses an animation for the same purpose, locating the current app window in a sea of others.
So what would the preview be in the swipe-from-desktop case? A preview of the window-sea, or the desktop as is? What should the animation be? I suspect those questions are why they chose to just name the desktop.
I think it would be more consistent if the tab based preview only existed for the desktop window-sea and transitioned to the actual space previews when swiping between spaces.