The bodies on the fence

At first I thought the people trapped on the fence were frozen corpses, but as Alexandros and the boy get closer to the gate, some of them start to move. This is very visible and it doesn't seem like an accident. What does it represent?
If this was indeed an unintended thing, like the scene in the morgue where Selim moves his mouth when he was supposed to be dead, it's a serious oversight, because it diminishes the power of the film.