"Full Screen Mode" is not really about full screen. It is an attempt to simplify the concept of virtual desktops, making it more intuitable to ordinary humans,

"Full Screen Mode" is not really about full screen. It is an attempt to simplify the concept of virtual desktops, making it more intuitable to ordinary humans, while also putting applications or tasks into a linear arrangement so that they may be navigated more easily with multitouch gestures (task switching).