So, I looked at this image because it intrigued me. The EXIF data is consistent with an original photograph taken with a Sony camera. I wish the optics on the camera were a bit better and the digital CCD since much of the resolution gained in this photograph is done through digital magnification within the camrea. When you go to native pixel mode you can see that there is a great deal of dithering and dot shift.

This is not any sign of foul play, but rather just a camera trying to increase resolution where the physical optics don't support it.

What does all this mean? It means I can't get too much detail, not much more than what you're seeing in the lower resolution thumbnail.

Now onto the content. Very interesting, I think you are all correct it looks like smoke or mist. That's not to imply that its neither paranormal nor non-paranormal. I do find it interesting that the vapor trail on the right shooting downward appears to be forcibly pulled downward even though there is no visible source which would naturally do that.

The vapor/smoke source seems to be somewhat in the near-field. In other words its closer than the closest point in the railing. However the whispy parts of the mist/cloud do seem to extend past the railing into the center of the room area.

This would preclude any source such as exhaling on a cold day or a smoker taking the picture. Since the feature extends well beyond the area which such a source could reach.

Also if we look at the EXIF data we can see that the entire picture was snapped in roughly 2/100ths of a second. So the likelyhood of it just being some object which traversed the camera's path, changed direction, and created patterns is very slim to NONE.

I would have to say its a very interesting image. I would like to see some corroborating data. No evidence can be an island. For this to be a viable and document-able result I would like to see some information such as ambient temperature if you have it. EMF readings if you have them. Were any EVP's caught during the time of this picture. What's the history of the location. Any sensitives in the area during the picture and did they sense anything? Were any video cameras recording during this which can verify the results or corroborate the environment.

Either way its a cool picture.