Why would you want to insert penworked letters, gold-leaf and illuminations on your legal document: company statues, a contract, a grant of land or even an indulgence? This may seem like a waste of time in the modern business context, but in the medieval culture visuals carried their own significance. The messages could be multiple. Look, it’s important, because whoever ordered or produced this document put extra time and materials into it! This document won’t get thrown away, because it’s so beautiful! It’s so rich, it must be authentic. Not to mention the visual shorthand the illuminations would generate for the document’s content. All of which, of course, could be highly misleading, because a forgery can get illuminated just as easily as an original, which I learned through my study of medieval Livonian charters.