Here's what George Broussard from 3D Realms has to say about this new screenshot:
Don't worry, all you ask for is there and coming. This was originally a level that Allen made and printed, to use as wrapping paper for our xmas party gift exchange. We thought it looked neat, tweaked it and released it as a wallpaper. There is a lot of color and whacky locations in the game. These are just some of the enemies. We're going for a non-cartoony style so you're not going to see lots and lots of color and camp on the enemies themselves.
It's a nice piece of art, but after 11 years we'd prefer to see the real game instead.