Motion depth cues : Parallax : Relative move

Motion depth cues come from the parallax created by the changing relative position between the head and the object being observed (one or both may be in motion). Depth information is discerned from the fact that objects that are nearer to the eye will be perceived to move more quickly across the retina than more distant objects.

Move of the viewer body is more important than the move of the object because of the proprioceptic feedback telling them how far they moved. When viewers cannot determine the rate of the relative movement between themselves and the object, their judgment is less precise.

Even a slight rotation of the head allows you to use that sort of cue