The premise of this book got me interested. 2 stories: 1 a renaissance artist in the 1460s, 1 a girl in Cambridge in the 2010s, half of printed copies got the Eye (artist) story first, the other half got the Camera (girl) story first. This is not a gimmick. The book is excellent, it doesn't need a gimmick.

The copy I read has the Camera first and I think it really made a difference in how I perceived the story. Yes, in spite of there being 2 stories, it is interlinked and really just one story. There is such a difference in writing style that it took me a while to adjust when I switched to the Eye, so much so I needed a day or so complete break to let the Camera settle. And now having read the entire thing, I'm going to spend a bit of time dipping back into sections to reread, and contemplate all the ideas it has brought up.