The marginalia of medieval manuscripts are often pretty wild. Just my personal theory, but I always thought it seemed like one of the places where the artists could inject a little of their own ideas, elaborating on the subject or drawing parallels, using symbolism, maybe little in-jokes for the client (hours books were made for one person), etc. Sort of like the extra panel of an xkcd comic.
The marginalia of medieval manuscripts are often pretty wild. Just my personal theory, but I always thought it seemed like one of the places where the artists could inject a little of their own ideas, elaborating on the subject or drawing parallels, using symbolism, maybe little in-jokes for the client (hours books were made for one person), etc. Sort of like the extra panel of an xkcd comic.