As far as I know, video compression works on areas, not just pixels. To me, it looks like it's trying to update areas of the photo by moving areas of pixels, i

As far as I know, video compression works on areas, not just pixels. To me, it looks like it's trying to update areas of the photo by moving areas of pixels, instead of just updating them individually. This is accidentally getting more than just the part that's moving, and making things nearby seem to move as well. For instance, in the video provided in another comment, when the climber swings his legs up a bit, there's a portion of the wall that stretches behind him, before eventually un-stretching back into place. It flows behind the moving limbs. I suspect that if good video were taken of the scene, the leg would also be somewhat distorted while moving, but we can't really tell because it's supposed to be changing, unlike the rocks.