On FIVE when you open the first door there will be lots of portraits.

There will be one of a guy in an olden day army uniform. Then on Nuketown, the same pic is on one of the desks in one of the houses.

Then on Kino der Toten, when you go first top door (where mule kick is), you will see pictures of Dempsey, Nikolai and Takeo along with a blank portrait.

Near those is another portrait of what looks like some unknown general.

Then on FIVE in the pack a punch room you can see the same portrait.