I would like to argue that there is something especially visually interesting about people when they’re reading. And there is: the faces of readers have an interesting commonality no matter where the reader is—a close attention to something right in front of them that produces a kind of otherworldliness. It’s the opposite of spotting someone in public who has a camera up and at the ready, where they are exclusively focused on something out there in the world to the exclusion of all else.
But this would also be a bit of an alibi about why I like to take photos of public readers. I like to do it because it relieves me of my principal anxiety in street photography or any public photography: a reader is distracted enough that I can take my shot and not worry about it.