Several months ago in art class, a video was being shown. I was not paying attention at the moment unfortunately, but I noticed the Dark Side of the Moon cover was being shown. It should the pyramid without colors, then it should the colors come from the left and went through the pyramid out the other side, so I'm guessing it has something to do with colors or something like that.

For covers, I wouldn't try finding some sort of meaning to them all. A lot of it is probably just some sort of idea that pops up into one of their heads.