Can someone explain the ending? *spoiler*

It is just a scary movie that isn't supposed to mean anything.
The guys actually went into this place back in 2009, after
a dinner conversation. They found it spooky, and thought
it might make a decent little horror movie, so the redid the
dinner in the movie, and them going out to the place, but everything
after they enter is all B.S., obviously, there is no such things as
ghost, but anyway, the ending is just an artsy way to end it, I don't
think it was a clever as they had hoped, but I liked the rest of it.
You have to remember, being the son of the guy who made Natural Born
Killers, you are bound to try something crazy in your movie, and
hope for the best. It was just your basic descent into madness,
is all it was supposed to be. We saw the Fedora guy right in the
beginning when they first walk into the place, it gave them their
first little jump. You also could see the fedora guy up into the
window before they went in. perhaps it was supposed to be something
like "They thought the ghost/madness was in the place before they entered,
but it was themselves who brought it into the place.





http://www.facebook.com/mike.d.keith?ref=profile

I don't think he was necessarily the same figure that had been following them.
Firstly, there were several different shadow figures shown. One looked like it was wearing a sort of bat wing cloak, another had spiked hair or head, etc.

Alex at one point said he thought that everyone has a shadow, and when you die an awful or tragic death, then a part of you gets stuck there -- your shadow. At the end, before showing Sean in a coat and a hat, it flashed back to the dinner party where Alex said that everyone who goes in there goes mad. We saw that Antonella had become the hag or "Crazy Kate," and I think that by then showing Sean walking away but leaving behind his shadow is how they represented that they all died in there. No one left. When Sean stepped away from the wall, he left his shadow behind. So as was mentioned earlier, he (all of them) died a traumatic death, and when his soul departed and walked away to whatever sort of afterlife, his shadow was stuck behind. He also just happened to be another "hat man" type of entity.

Both the "hat man" and "the hag" are commonly seen and reported entities.