Triptych
I loved Mike Kaluta's covers for Aquaman... as pieces of art. As covers, they didn't really do their job. If you are a reader looking for a book to pick up, you look at Kaluta's covers and say, "wow, neat!" then move on to the next book in line, one that has a cover that makes you want to read the story inside. A cover that makes you wonder what's in that issue.
Pin-up covers are fine for high-selling books, but for any book that's losing readers and close to cancellation, like Aquaman was when Kaluta took over as cover artist, you want something that will make the readers take a second look. Something that will make them want the answer to the mystery that the cover sets up.
I love Mike Kaluta's covers for Aquaman... but they never made me ask "what's going on in this book?"