When going through the engine room, you will eventually find yourself underneath a Russian guard that is standing on a ledge hanging above you. If you watch his pattern, you will notice that he is using binoculars to look at the wall. Look around the wall behind you. You will notice that he is looking at another one of the pictures of the Japanese girls. While he is looking at it, shoot it with any weapon (preferably the silenced USP if available). When you shoot it, it explodes. Note: Doing this sends you into alert mode; be prepared for the backups.