In an interview with Comic Book Resources before publication, Kidd said:
The one thing I did that he [Dave] said he really liked was that -- and I don't know how else to do it -- I didn't do a script that looked like any normal comic book script I know of. In other words, it doesn't look like a movie screenplay. I diagram all the pages out. It's very specific with me showing "This is how big this panel is, and this is what's happening in the panel, and this is the dialogue." Dave said he liked that because it did a lot of his work for him, and that was the idea -- to put as little guesswork in as possible.The image above is from the back of the finished book showing a page from Kidd’s script. Each box is a panel, with a description and speech balloons in small type. Taylor sketched his ideas for those panels in the spaces. (Andy Khouri reported for Comics Alliance that “Kidd said that he also included sketches but that Taylor rightfully asked him to stop.”
But where he pleasantly surprised me was where he would deviate from that. There's actually one big huge deviation at the beginning of the book that just shocked me, and it didn't make me angry, but I had to go "Hmm. Wow."
Kidd discusses the book’s look in more detail in another CBR interview.