No foul, both AIW and that game in that link got the image from a free source of images
Daniel Cook is the artist, and the original game to use those images was Tyrian, way back in 1991. I grew up playing that game.
I'll take a stab and guess you have Open Tyrian installed on your hard drive then?
Actually, no, I have the original Tyrian in my closet somewhere. I originally bought it on 3.5" disk, and it's still on that. Not that I have a disk drive of that sort handy at the moment, either, but I probably do somewhere. I still have a couple of boxes of stuff on that format as well as 5.25" (including the first games I ever wrote, in QBASIC, on the latter). And including all the Demon Stalker levels I did, on the former.