Glass door, perhaps he's watching the guy put his mask on prior to entry.
I recently needed to physically return my WiFi pizzabox to a Spectrum store, which also sells cellphones.
They had an interesting strategy to ward off potential thugs.
As soon as I entered the store, two clerks in the back told me to sign in electronically at a terminal in the front of the store. That little precaution enabled them to see that I was indeed a customer who had recenty cancelled by high-speed internet service.
The clerks were located at a desk 75 feet away from the front door. They were close enough to an exit door to bail if I looked like a criminal.
Such is life in the Wild West.