Changing Strokes

A true morning giggle and opened eyes. Is the image a duck or a rabbit? If I see one and then the other, has the image changed? Each stroke the same, not a one moves yet change is what I see. Perhaps Wittgenstein was drawing neither. And if my brain's perception can be so fooled by simple strokes, how does it see others, events, actions, even my body in a mirror, and the cornucopia of Life itself? 

*image retrieved from http://www.clas.ufl.edu/users/glue/longman/2/duck.gif