how did I do this

[stuigi]

This has happened a few times and yet I cannot recreate the action to do it. I get a screen with a frame around it with a border on the right, top and bottom with action buttons. Does anyone know I get into this mode?

 

[Rukbat]

Settings/Controls/One-handed operation

Then you swiped the screen. (You can read about it once you get to the above screen.)