Why is my Galaxy s5 display doing this?

[akdeyoung92]

This usually happens when I am trying to unlock my phone (swipe pattern). The best way I can describe it is that is is almost as if the screen is getting into a smaller window that can be expanded/shrunk with black surrounding the smaller window. Think of it like you have your internet browser open on your monitor and you can still see your desktop and icons because it isn't expanded to the entire screen. So my "desktop" would be the black area and the white box part is the outside of the "browser window". I'm sorry if this description is terrible but I can't find it in settings anywhere so I don't know what it is called. I know that it is not the multi-window feature because it does not look the same and I have my multi-window disabled. I am running on android 5.0.

 

[SpookDroid]

Under Settings, Device, One Handed Operation, do you have the Reduce Screen Size option on? If so, this works with a swipe gesture from the edges. However, it should only activate if you do a quick swipe from the edge and back into it.