I was recently browsing through reviews on Goodreads, hoping to have found someone that managed to get a hold of an early copy of the book, Escape From Lucien. As luck would have it, a reviewer named Nori did just that recently. Her blog can be found here.
I assume to avoid spoiling the story, she gives us pretty much details we've already been given over the past few months. However, Nori also adds that her new favorite character is an "elf girl mayor" that she found to be "so cool". I assume this is the character in the backdrop of the book's cover. Looks like my hopes for such a character have been fulfilled, so yippee!
I also assume this is the mayor of Lucien, but I could probably be wrong.