Sometimes for composite shots they’d move the camera instead of the subject. For example, if you want to make it look like a guy is falling to his death you can have him lying on his back flailing his limbs on a green screen floor and then quickly yank the camera upwards a few dozen yards so from the camera’s point of view it looks like the actor is falling away.
So for something like this, perhaps they put Pryce on a suspended rig that let the wings flap up and down and then panned the camera around him, then composited the cloud scenery in to make it look like he was moving against the background. It would be interesting to see the making-of though.
