Have you ever noticed matching book covers? I was in Walmart one night and stopped to pick up a book that I thought I had read before. (Why was I picking up a book I'd already read? Because I loved it so much I just wanted to hold it in my hands and look at it and maybe sniff it a little.) Turned out it wasn't my book at all but a completely different one with THE EXACT SAME COVER.
Ever since then, I notice this phenomenon all the time.
This is the cover of Onyx (which my BFF calls "alien twilight"):
And this is the cover of Significance:
YOU SEE WHAT'S GOING ON HERE, RIGHT?
These authors. They think they're so clever.