featherless
Explanation
This comic plays on the famous philosophical anecdote about Plato and Diogenes. Plato once defined a human as a "featherless biped," whereupon Diogenes the Cynic reportedly plucked a chicken and brought it to Plato's Academy, declaring "Behold! A man!"
The comic transposes this joke into the age of dinosaurs. A feathered dinosaur (likely a dromaeosaurid or similar theropod) is shown walking through a prehistoric landscape carrying what appears to be a cup and a book. In the final panel, we see the dinosaur is reading a magazine or book titled "FEATHERLESS" that features an image of a non-feathered dinosaur (like a sauropod or similar unfeathered species) on the cover.
The joke works on multiple levels. First, it inverts the Plato/Diogenes joke: in a world where feathered dinosaurs are the norm, a "featherless" creature would be the exotic oddity -- essentially a dinosaur equivalent of a pinup or novelty magazine. Second, it plays on our modern scientific understanding that many dinosaurs (especially theropods) actually had feathers, making the unfeathered depictions from older paleontological art amusingly quaint. The feathered dinosaur is looking at the "featherless" dinosaur the way a person might look at a risque magazine -- the joke being that in a world of feathered creatures, being featherless is scandalous or titillating.