Sign into an existing account

It's the other way around. That was a practiced move, one that was understood between the guard and the other man, who was a sergeant or a lieutenant, but obviously a superior to the guard. The guard was informing him that he would stand down long enough for his superior to cross the line to retrieve the glove. It was theatrical, to be sure, but it was has to be so that everyone can see his movement and intention. He's not there for show. It was a respectful gesture to his superior, who clearly understood its meaning. He was not going to cross the line until the guard told him he had the go-ahead.

Yeah it might have been a maneuver they're supposed to make in the presence of a Beefeater/Yeomen Warder (which I think the gentleman was).