On the first half of the Jerusalem level, there is a book store directly behind an alley with a swinging lamp. Next to it is another smaller alley with a swinging lamp. If you look inside the large window you can see many different picture references to The Punisher, Ubi Soft's XIII, an anime, and a picture of the infamous "Sniper Kitty" among many other things. Use the binoculars to get a much better look.