This makes it all the better, especially when you did not see anything in the room or your surroundings and it turns up in the photo.
Because you are a photographer; this pic is even more interesting. I believe that you would have found a rational explanation if it regarding photography (ie flash, double exposure, reflection etc..)
I am not trying to freak you out any more but I also cannot make it out.. whatever it is, it is spooky. I am a firm believer in the paranormal & believe that spirits & entities come in many forms.. You may have captured one form of spirit energy.
Have you been back to this place to take any more snaps or check out the room?
PS..which facebook site is this on? (if you are allowed to mention)