As you can see, famous paintings have had books added to them, and in paintings where there are people, they now appear to be reading or have been reading. That is, each of the twelve designs on these 'Master the Art of Reading Bookmarks' features a literary interpretation of classic works of art.
My set is all labeled as being published by the "Lab Safety Supply Inc., in 2007-2008 but my understanding is that the original set of 6 was first published by Demco.