You've found the explanation place!
The things in line behind this thing are our Art Prints. That's sorta shorthand for "anything we make that isn't client work with a band name or a movie title on it," and it covers everything from things we're commissioned by other people to make, to prints we make for gallery shows, to text-less versions of client work, and totally self-initiated things that we make for no reason at all.
This "Art Prints" item is mainly intended to serve an organizational purpose, but has to have a price on it (because this thing isn't built to have items without a price on them, and marking it "sold out" seemed confusing), so we've decided to set a couple options in here to establish the range of prices for these new things we've made.
Note: You're correct that this weird thing is purchasable. That's not really our intention (or is it?), and it's definitely a byproduct of the way the backend of this store functions, but, because we love fun, and we love doing weirdo stuff, I'll tell you now that if you order one of these "things," either out of sincere curiosity or as a goof, we will send you something. Totally up to us, could be cool, could be dumb (but we'll do our best to make it cool, as we always do). You get what you get, no refunds or tag-backs, no more promise, no more sorrow.