What's the purpose of the green square, anyways? Why not just have a regular camera feed?
Increase deterrence effect to scare away shoplifters. Home depot goes out of the way to make its cameras visible. There is a large "camera" sign, bright light to catch your attention, a visible display to show it's not a fake, and sometimes even a motion activated chime. I assume the green square around the face is the next step in a game.
also locked cabinets... cause me to not buy whatever is in them.