What do you see on penta from doom3?

What do you see on penta from doom3?
http://prboom-plus.sf.net/pentastic1.png

1. Face from Doom status bar
http://prboom-plus.sf.net/pentastic1_doom_face.png

2. UAC texture from door on map01
http://prboom-plus.sf.net/pentastic1_uac.png

3. Cassiopeia (constellation)
http://prboom-plus.sf.net/pentastic1_cassiopeia.png
http://en.wikipedia.org/wiki/File:Cassiopeia_constellation_map.png

Thanks for spoiling the puzzle.

OTOH, that's what makes Doom 3 so damn good to play. All those surprises are hellbent to make you replay that goddamned game.

There is also a demon's head in the middle.