During my short trip to London I discovered that Victoria Coach Station has separate departures and arrival terminals on opposite sides of the road. I was puzzled - do the coaches all have to cross the road to pick up the next lot of passengers? The blip is inside a third coach terminal, which both drops and collects passengers, diagonally opposite the departures one. Then some coaches drop off and collect from the main road in the middle of this lot. It must be a monstrous scheduling job to make sure they don't all snarl each other up.
As it happened, one of my fellow passengers back to Oxford was a coach driver in uniform who happened to be interested in the history of bus travel so he answered all my questions and some. The arriving coaches go off to a depot to be cleaned before coming back to collect more passengers. And the logistics are far easier than they used to be. Allegedly there were once thousands (I don't believe this) of dropping off and collecting points in this little bit of London.