Here is a page from my pocket notebook of Mac Barnett and Jon Klassen discussing a new picture-book version of “Hansel and Gretel,” which was made by Stephen King adding words to Maurice Sendak’s designs for an opera.

JON: I’d say the illustrator is in the business of reacting to the text, doing work the manuscript doesn’t do. This can mean providing new information, adding a different tone or even subverting the words a little.

MAC: It’s this fluid, playful dynamic between text and image that...