Any time you have to divide up a range of things into distinct buckets you get weird corner cases. Many states tax restaurant meals different from groceries and thus must decide on where the exact difference between buying a single donut (this is obviously food for now and this treated like restaurant food) and a dozen donuts (this is food for later so obviously a grocery).

Comic books are much more "magazine like" then "book like" in practice so it's not surprising they are treated similarly.