In Windows 11 or Windows 10, when you have one or more windows open for an app, to see thumbnail previews of the open windows you can hover over or click/tap on the app’s icon on the taskbar.

Learn how to change mouse hover time to show taskbar thumbnail live preview in Windows 11/10 using Registry Editor.

Another feature Microsoft silently axed from Windows 11 was Windows 10's Desktop Peek, which allows users to show the desktop by hovering the mouse cursor over the extreme right end of the taskbar.