Once you learn the iconography it's hard to unsee when you look at almost any piece of art from that period. John has the eagle, Mark the lion, Matthew the angel. That's why St Marks square in Venice has a lion, for example.

Since we are talking nonsensical images with books, heres one of the eagle of St. John settling down for a nice read.

https://www.gettyimages.com/detail/news-photo/the-eagle-symb...