Ye Olde Sale Shoppe

So this is interesting...after I uploaded this same photo to my Facebook account, I noticed the shadow at the door. When I took the photo, I made sure there was nobody in front of the store. I'm trying to figure out what caused this one shadow, because it really looks like a person walking up the stairs, but that can't be. There is nothing in the middle of the walkway. It could be a shadow cast from the pile of stuff on the right, but I didn't use a flash...I'm stumped. My other photos from that night don't show this blob, so it isn't a smudge on the camera or dust.