Angel Wing Picture

Tuck sent us this very cool and interesting image. Is it an angel picture of an angel wing or did something else get in front of the lens and reflect the flash? You decide...

"This was taken one afternoon in 2002 while we were in the process of moving into a new house. Our son was playing a video game on a hastily set up TV, and my wife took a photo of the otherwise empty room."

What the heck did they capture in front of the camera?  It's clearly reflecting the flash...but what caused it?