Hand On Back Ghost Picture

Lin sent us this ghost picture of a man with his hand on her son's back. The problem is there was no man in the room with the three of them:

"Please tell me if this is a ghost, a sprit or what it is. This picture was taken with a digital camera. There were three people in the room. My son is sitting on the floor w/ the hand on his back, his girlfriend is across from him, and a friend took the picture. The image is a man with glasses (we think) ~ we do not recognize him at all."