Inward moving square Illusion

David Cherry (whose Unreal Movement Triangles we already covered) created something we haven’t had the opportunity to see for quite some time now. His “animation” effect works flawlessly! In order for you to see the effect in its full glory, I was forced to edit David’s original attachment, yet it’s still available if you click on the picture and open it full size. Am I imagining things, or does the phantom cross really appear to continuously shrink?