If it truly is a spirit [which like you I'm not too convinced at this point], I don't think there would be a reflection or shadow. Is it possible there is something to it? Sure there is.
I have seen spirits in photos which were this dense; I took a photo which our resident physicist CC actually showed me I had something and I didn't know it. It was that dense; that's the only way I know it's possible.
One thing I would question is why is the figure in black and white?