I sort of agree with ima and others... the gnome is for sure fake as hell, but the kids sitting there had no idea they were in a prank.. maybe not even the camera guy... probably someone in the group said "hey, why don't you film us here for a while", knowing that would be the key for the other guy to start pulling the prank...
ahh, who knows... I saw the ghost thingie... and it's interesting, but it could be so many things other than a real ghost... I'm thinking some type of reflection caused by something in there...

luckily this is all OT ^_^.. but yeah, that damn gnome creeped me out regardless... I only could watch it once xD