It's a man-trap. When I worked with the police department and visited the communications room or other facilities, you'd be allowed in one door that would lock. You're trapped between two doors in a small corridor (with cameras watching). Only if you're authorized, will you be permitted through the second door. Very effective security. They should have this at convenience stores at the front counter (separated by security glass). Go through one door, pay, and only then be able to leave through a second door. A man-trap corridor where the clerk is safely behind security glass.
There are gas stations that don’t allow customers in after a certain hour (maybe 10pm on weeknights and midnight or 1 on weekends, if that).
They have a tray/door that allows cash to trade hands, credit card receipts to be signed, and Red Bull, cigarettes, and chips to be dispensed (like at a drive through at the bank).