What's or who is standing in the middle of Stonehenge?

Recently on the Writers' News Talkback site, we were discussing pictures which have strange things appearing on them. I added my story about the photo of something standing in the middle of Stonehenge, when you were kept a distance by a cordon around the monument. And minders were strategically placed around the monument also. So I wonder how this person, thing or alien appeared in the centre of the circle? I've zoomed in and it looks like a person with some kind of breathing tube on their head. Your comments are welcome. What do you think?
You might have to zoom in and take a look, but you can just make out the figure between the two short centre stones.