Abridged transcription of his talk about the different affordances of various media, especially books and screens. For the former, written text is foregrounded, whereas images are foregrounded for the latter.
M. May, and J. Petersen. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), volume 4604 of Lecture Notes in Artificial Intelligence, page 220-240. Berlin, Heidelberg, Springer-Verlag, (July 2007)