It looks like zoom. Does zoom look different than this?
Anyway, try going into Settings > General > Accessibility > Accessibility Shortcut and add zoom. Then if you encounter this issue triple click the home button to see if it helps. It could be turning itself on.
Or, you could try fixing it by resetting all settings or restoring your iPad.
I also have an app that when I open the live video, it opens a little too big for the screen. The edges go off the screen. When I shrink the video, it fits. Weird.
I have turned off zoom, deleted the app and redownloaded it. I have also reset the entire iPad.
The first image (1D769191-...) is the minimized window and the second is full.