After being exposed to a lot perverted content, when one observes the picture, one sees a man caressing a woman's bosom. However, a person not exposed to such content does not see the couple; rather, the person sees black dolphins. A more perverted person may be able to see the dolphins after six seconds.
something that deceives the eye by appearing to be other than it is
The artist spray painted the wall and the floor. The stairs only look 3-d from this angle.
Depending on the way you look you notice the window opens from the right or the left.
When you move close to the you see the distint features of Albert. If you move far away from the photo, you can see faint features of Monroe.