Perspective. We have no way to judge how far back from the platform that tree actually is.
I considered that, but assuming the man is looking at the tree, and seemingly in a direction perpendicular to the camera’s line of sight, it seems the tree and the man are about the same distance from the camera.
Another possible explanation: the base of the tree might be significantly wider than the part of the trunk we are seeing. I think Cyprus trees tend to flair out quite a bit at ground level.