What is the effect of an absence of familiar subjects in the image?

The eyes are so quick that it was hard not to read the caption :-). Anyway, it is an image where the mind does not know what is in photographs for the first glance. The printed image is also "small", and I had to lean my head closer to see what is there and I was not sure what it is. For the familiar objects are missing the picture captured me. I want to know more, I guess it is a dark place where the light goes through a hole in the wall or roof? What is the object in front, at the bottom of the photograph? Can I have more information?