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.
A few days later I get an email "your item hasn't been picked up and you've been refunded."
Apparently if you scan an item and pay for it in the store they still expect you to wait for their staff to approve you, or something. It wasn't clear.
This was also only necessary because they didn't accept Apple pay so I had no way of paying for my items except through the app.