Unreal 2 Easter Egg - Glowing Face with Eyes

Inside the Atlantis, to the left of the hallway leading to the cockpit, there is a pile of boxes. Directly above this pile, hidden behind the ceiling panel, is a glowing face with glasses and non-glowing eyes. On closer inspection it's guy with a beard, but who? Likely "Cliffy B.", whose face appears in Unreal games, but it's so washed-out (from a camera flash?), who can tell?

There's a narrow slit where you can catch a tiny glimpse at a time of the face, or you can use the 'ghost' cheat to move up and through the ceiling for a better look.