The issue here could be what version of the game they're using; as far as I can tell, that scene on the right isn't in the latest version that you can easily find on the net (or at least I couldn't find it after a cursory search of the usual places). This game is kinda messy when you extract it, but I couldn't find a trace of that CG after combing through what I could see.
That isn't to say that the extractor missed it (I used GARbro, since the RPG Maker extractor/decrypter doesn't seem to like the game's file names and crashes when you try to use it), and it actually is in that version of the game, but everything else I'd seen in the game was there in the files, and I haven't been able to trigger it with a copy that was uploaded around June of last year (version 1.2.1, at least according to the uploader), no matter what level the heroine's pollution was at when I did the fight.