A favorite book of mine as a kid was called CDB by William Steig. My mom brought home a copy of this book before I went to school (she was a volunteer librarian at the Campfield Elementary School).

This told simple stories with just a picture and a caption, but the caption was a sentence made of words– the title cover was a picture of a girl talking to a boy and pointing to a bee floating above a flower. She is saying “See the Bee”, but Steig write the caption as C-D-B.

I did not realize this at the time, but this is a model of simple (within a limited context) multimedia storytelling.