Dilbert often has single-punchline strips where the punchline is spread over multiple panels, followed by someone commenting on the punchline. The punchline is usually that Dilbert is the smart straight man and everyone around him is incompetent (The same thing is made fun of in the pony comic). Finally, Adams has a bad habit of drawing his characters chest-up, hiding most of the character behind the desk or the edge of the panel (so he does not have to draw hands).
Those are the the things made fun of in the zippy strip, first the characters point out how you only see the top of them, then the “joke” is a jab at the repetitive punchlines, then the boss follows up with a nonsensical comment on the punchline. The stilted speech and Zippy standing behind the corner in the final panel are more in line with the Zippy comic strips than with Dilbert.