It appears to either be a trick using night vision technology, or perhaps something was really there.
What a spooky story it would make if someone where to be able to see strange spectral creatures through his camera lens that are invisible to his naked eye. One way this could be done is by using night vision. This method of seeing in the dark is popping up all over television reality shows, such as Ghost Hunters on Sci Fi Channel and Most Haunted on Travel Channel. Usually the camera is strapped to the individual and focused on their face in order to get their reactions as they occur.
Night vision works by adding extra light to what is being seen. The way it works is rather complex, but this technology that was previously only available to military personnel, is now available to the general public and many video cameras are now equipped with a night shooting setting.
Which brings me to the video at hand.
The authors of this footage seem to have captured something quite mysterious here. At first, it appears to be a reflection, but then it becomes apparent that this isn't the case. After it disappears, it becomes more obvious that this is a ghost unexplained video.