(Strip Number 7177, Original Publication Date, 17 February 1985)
Panel 1: We find ourselves watching Mike and Lawrence building a snowman. Having noticed that he seems to be doing all of the heavy lifting, Mike accuses Lawrence of not helping him push the largish lump of snow that they're making.
Panel 2: Lawrence refutes this assumption by pointing out that he's making grunting noises.
Panel 3: The strip proper begins when Lizzie asks if she can help our heroes.
Panel 4: Since Mike is a nine year old kid (and a bit of a jerk anyway), he tells Lizzie to get lost. Since Lawrence is also a nine year old kid, he joins in in telling her to hop it.
Panel 5: We next see Lizzie sucking her thumb as a means of comforting herself because her primary caregiver has suddenly started rejecting her just like everyone else does. Were this the sitcom Lynn likes to think it is, we'd be hearing a pre-recorded snippet of people going "AWWWWWW!!!!" in sympathy.
Panel 6: Lizzie's response is not to run to Mommy to FORCE Mike and Lawrence to let her play too but to make her own snowman.
Panel 7: We next get a dialog-free panel that has Mike tell John and Elly to come look outside.
Panel 8: When John and Elly praise Lizzie for her little tiny snowman instead of the big one they built, Mike and Lawrence stand there frowning in confused disgust at the unfairness of it all.
Summary: This, I should think, would cause Mike to relapse into his old habit of whining about how people praise Lizzie for nothing when he can do more. Since his brain is tiny, he doesn't see that he isn't actually being slighted as such but instead is being asked to praise Lizzie for trying. He also doesn't realize that he's the son who'll always outshine everything she ever did or ever will do because he's kind of an idiot.