Right Hand Man

This morning while I was in the shower, I saw something I had never seen before...When I opened my eyes after rinsing the shampoo out of my hair, I saw out of the corner of my eye that my right hand had made a perfect shadow puppet of a lion on the wall. When I turned to look at it more closely, it was gone and no amount of trying could bring it back. Damn you hand, you've been holding out on me. How did you do that?