I'm pretty sure that is a rusty sheet metal wall and even if it was marble, if you examine the monk figure up close you can see the transparent apparition extends beyond the wall as he moves so it's not a reflection in the wall at all.
edit: Actually, the wall in front of which the apparition appears isn't metal I think, but it's academic as the apparition extends beyond the edge of the wall like I said.
However, my first thought was that it's very suspicious that he stopped and held the camera still for no apparent reason, just as the apparition appeared and then moved on just as the apparition disappeared. Looks way too much like a deliberate setup, hold the camera still so it's easier to use video editing software to insert a 'ghost' that would be much harder to insert if you had to make the ghosts movements match the jerky camera movements.
It's not like he saw the apparition and stopped to film it, as the description says it was taken by a family who only noticed the apparition after they viewed the footage.
Edited by Archimedes, 21 August 2012 - 04:49 PM.