Here's the details that Cassie shared about the cover via Tumblr:
- Tessa is holding the Shadowhunter Codex
- The setting in Clockwork Princess remains the United Kingdom, with mentions of some more faraway places.
- She can’t reveal models’ names, as usual, but her dress isn’t available for purchase; it was borrowed for the shoot from a costume collection. Cassie said: "It’s beautiful, no? Clearly an evening dress. Victorian evening dresses were shockingly low cut. Footmen sometimes had to help ladies out with wardrobe malfunctions."
- More on the design and the pendant (or lack thereof): "Tessa on the cover here isn’t supposed to represent specifically Clockwork Princess Tessa, but Tessa throughout the series, so I never thought of specifying she be wearing/carrying the things she has solely in Clockwork Princess. Tessa’s dress design, what she’s wearing, all were done by the artist without input from me. And he hadn’t read Clockwork Princess, because it hadn’t been written. He was going off the other two books. No engagement ring (well, there isn’t one in the book anyway, the pendant stands in for it) and no pendant doesn’t mean anything, one way or another"
- Tessa is standing in front of Blackfriars Bridge and St. Paul’s cathedral.
- About the ring: "I just checked back in Clockwork Prince and yep, she never gets an engagement ring except in the scene where they go to York, but she gives it back. Just to say!"