The window being minimized animates.

It goes from bottom to top of the window with a continuous effect, it squishes down in width then gets warped/pulled to the dock icon to minimize.

The effect is like when Genie from Aladdin enters or leaves the lamp, but without smoke.

Sorry, It is actually called magnification effect (I am not a Mac user).

https://www.youtube.com/shorts/eOrvbaKz5H4