The Hidden Windows
When you click the yellow “minimize” button in the top-left corner of a macOS window (or press Cmd + M), the window shrinks down and places a small thumbnail of itself on the far right side of the Dock, next to the Trash can. However, macOS includes an alternative option called “Minimize windows into application icon.” When this is enabled, minimizing a window doesn’t create a new thumbnail; instead, the window seemingly vanishes, shrinking directly into the application’s main icon on the Dock.
While this keeps the right side of your Dock perfectly clean, it can be incredibly confusing if you aren’t used to it. Because there is no visual thumbnail indicating that a window is minimized, you might think you accidentally closed the document. To get the window back, you are forced to either right-click the application icon and select the hidden window from a text menu, or use Mission Control. If you prefer the traditional behavior where every minimized window gets its own visible thumbnail, you must disable this setting.
How to Restore Minimized Window Thumbnails
You can change how windows minimize via the Desktop & Dock settings.
- Click the Apple Logo in the top-left corner of the menu bar and select System Settings… (or System Preferences).
- In the left-hand sidebar, click on Desktop & Dock (In older macOS versions, simply click on “Dock”).
- Look at the very first section of settings in the right-hand pane, which controls the Dock’s behavior.
- Locate the setting labelled Minimize windows into application icon.
- Toggle the switch to the Off position (or uncheck the box).
Now, whenever you minimize a window, it will fly over to the right side of the Dock and sit there as a clearly visible thumbnail, allowing you to click it and instantly restore it to your screen.