When you press the "Shift + U" hotkey, the GUI is transformed to show most of the game editor's elements in their original size and position.

It's possible to drag and reposition elements, resize them using the mouse wheel, and change their size by using the hotkey.

It's also possible to drag the main window to the left or right and close it.

If you enable the HUDitor, it's possible to use the left and right buttons on your keyboard to toggle the next or previous element.