The camera in this shot sweeps towards the protagonist as it centres on him (Pitt), and away from the zombies as it switches back to them, giving the impression of speed and approach as the camera moves down the steps. It also seems like a kind of shot reverse shot (sorry if i'm completely wrong using this term, have very little terminology to grasp with) in that it shows the same scenario but switches between two views. Want to use it in an essay to describe how the camera moves from a view of the singular (Pitt) to the many.
Any help appreciated! The gif of this particular shot is provided here: