Look closer, as there's some breakable items that are hiding something.
Yes, there's a wall behind him. And almost exactly behind the point where he stands when you enter, there's a small retraction with a hole in the ground - there might be some crates or barrels blocking the view. You need to jump down that hole.
I usually break all the things in a room, can't help myself when playing Demon's/Dark Souls. But i'll check again, maybe it was too dark, i'll turn up the brightness, but the dithered colors are gonna be more apparent. You can easily see it in the screenshot I posted. Don't remember the PS3 having that problem...
Thanks.