The article is about infants. The idea that the images on the page even describe anything is a more advanced and abstract concept that comes later, developmenta

The article is about infants. The idea that the images on the page even describe anything is a more advanced and abstract concept that comes later, developmentally. Think of pointer indirection. Mimicry comes first, so an infant can learn that when they see Dora they should say "Dora". When they put something down or finish eating, everyone seems to say "all done" and clap, so they start saying "all done" and clapping. There's a whole range of sophisticated seeming behaviours that can be trained easily by simple mimicry. So, wrt. to reading. Things that infants can learn easily are picking up / putting down / fetching books. The nice feel of sitting with a parent and a book (which will hopefully lead to favourable thoughts towards reading, later). Also, mimicking sounds that parents make on specific pages. E.g. "BOOM, BOOM, BOOM, Mister Brown makes thunder" might trigger "BOOO BOOO BOOO". Think about it this way -- imagine reading with an infant. You could substitute / make up all of the words but go through the motions and they would imitate your words instead of what's in the book. I.e. mimic conversation in context. They really have no idea of the content of the book, or even that it's significant, compared to all the actions / conversation around the activity of reading a book.