Visual Representations of "Swan Song"

These are a few covers of my favorite book, Swan Song by Robert McCammon, first published in 1987 but currently out of print. The covers have always baffled me.

I used to own the top left one, and when I first read it, I waited patiently for this red-faced demon to rise over an ocean in some way, to no avail. There is a monster/demon in the book, but his face shifts from one normal face to another, and in between faces, has a third scarlet eye in the middle of his forehead. He's called the Man with the Scarlet Eye, but evidently the illustrator only used "scarlet" and "man." (There's also never any bodies of water.)
The bottom left one makes a little more sense, because Swan, the title character, is a young blond girl who makes plants grow in the post-apocalyptic world wherever she goes. However, the monster in the sky is again a very odd interpretation.
The bottom middle one makes no sense whatsoever, and I'm not sure what the illustrator could possibly have been imagining the book was about. Rest assured that there are no wolf-gremlin-mutants with green tentacle-tongues anywhere in the story.
The top right one is decent. This book is about the nuclear apocalypse between the USSR and the USA, so the mushroom cloud with the skull is appropriate. There are also several characters in the shadow of the cloud, and what appears to be a tree in the middle, so it seems that the illustrator really did pay more attention to what the book was about here.
The bottom right one resembles some of the action books we were looking at in class, with the very large fonts, but has not much else going on at all. It has a "best-seller" look, implying that the (late) author's name should be good enough to pique an interest in the book.
I currently own the top middle one, which is my favorite. The destruction of the skyscrapers of New York City, which is where one of the three main stories of the book takes place, is shown really well, and I like the addition of the bare tree in the foreground. I think this cover gives the most useful information about the book--just by looking at it, you can safely assume that it involves some kind of modern apocalypse. Although the top right cover also gave a lot of information, most of it wouldn't make sense unless you'd already read the book.

I chose this book because there's so many wildly different covers to choose from, most of which seem to have originated from a brief skimming of the 900+ page book. We didn't talk about the horror genre in class, but the artwork for most of these are somewhat typical horror-book covers: they look hand-painted, and usually have either bright, contrasting colors (especially if they're from the 80s) or shades of black, brown, and/or green (to convey a sense of the "night" or general shadiness in topic). But beyond being able to tell that it's probably a horror book, it's very hard to get an idea of how phenomenal this book is from just the covers, which are usually something that look like they'd be at home in a bargain bin.