It isn't a ghost or a demon, it appears to be a person. Just a normal everyday common-or-garden person. Frankly, I suspect you are having you're leg pulled by this chap, did he have prior knowledge of your paranormal beliefs?.
Anyway, rest assured that there is nothing strange here and try not to let yourself be scared of the non-existent supernatural, you are far more at risk, as in this case, from the corporeal people around you who will try to scam or upset you for no better reason than human nature.
Of course, this is just my opinion.
P.s. That 'ghost' looks quite a roly-poly apparition, has she been eating to many ghostly pies?.
Edited by Reverend Clog, 15 October 2010 - 08:52 AM.
If it looks real, feels real, can be photographed from multiple angles and is apparent to multiple independent witnesses and is reproducible within context, then its probably real.