The photograph issue

My roommate has this picture of himself taking a leak on the beach when he was a little kid. Not only that, he keeps it on the mantle above the fireplace in our living room. I don't know why he feels the need to display it either. The picture was taken from behind him and he has his pants around his ankles while he's holding the bottom of his shirt in the air as his bare ass showing while he's taking a piss. It's the classic little kid taking a leak at the urinal pose. So, my roommate feels the need to display this photograph of himself as a child. This got me thinking though, is this child pornography. Is my roommate displaying child pornography in my own house. I have a feeling that, technically, this is child pornography. I mean, it's a little kid's bare ass. Maybe it wouldn't be construed as child pornography because it's a picture of himself. I don't know if there's any law against having naked pictures of yourself as a child. I'm sure it doesn't matter even if it is yourself. I don't mind if my roommate has this photo, but he should probably stop displaying it for everyone to see above our fireplace. He treats it like it's a freaking family photo.