Near the end of the film,Kelly and company have no other way to get into the bank and persuade the German tank man to blow up the door. He does this and when they enter through the breached front door, it shows other soldiers already in the building coming in through a side door in the bank.
I have no idea WHY a bank would have a wall mirror in the lobby, but that's what it is. You can make out KELLY in the front, and he's the ONLY ONE with that kind of jacket in the whole group.