Rather than the mountain I think it's the imagery thats apparent here. Look at the windows. The middle one is taller than the two on the side, representing a jester head. As well as the three people there.
It has been in the booklet of those albums that it hasn't been on the album cover. Might be the case with Whoracle as well.Come to think of it, the jesterhead isn't on the cover of Reroute, STYE, or CC. In fact, they brought it back to being on cover artwork with ASOP. Funny how that worked out. As for the mountains in the back being from TJR, I don't think so. I see some pyramid-looking things, but not the mountain from TJR. Might just be my eyes, though.
It has been in the booklet of those albums that it hasn't been on the album cover. Might be the case with Whoracle as well.