I've heard that it's just a poster on the wall in the original Killzone game, as you can see in the top picture here:
Uhmm that picture you posted is obviously a photoshop. the tape over the poster overlaps with what would of been visible in the original screenshot there is no parallax distortion that one would expect from a 2-D image on a 3d surface at an angle and the wall texture is bland. the gun is also blurier in that picture. I hope you posted that as a joke.