(Strip Number 1458, Original Publication Date, 12 June 1989)
Panel 1: We start things off with Liz being excited because Elly hauled out the old photo album. Elly explains that she was showing them to Anne and forgot to put them away.
Panel 2: She directs Elizabeth's attention to a photograph taken during her second pregnancy and tells her "Here's a picture of Mike when he was little and I was expecting you." Since I'm not sure that Liz knows any other meaning for the verb "to expect" aside from "anticipate the arrival of a known quantity", her marveling and asking "You WERE?" sets off my gobsmack senses.
Panel 3: We look over Elly's shoulder to see an old black and white photo of her Heaven alone knows how many months along standing next to Mike as he plays on a swing set. As she thinks back to a past wherein he wasn't angry all the time for some baffling reason, Liz asks "Mom?"
This furthers my sense of dread because when a child character does that, Elly is about to get an unsettling reminder that Elizabeth don't know the same thigngs she don't know. Since this never quite manages to stick, Elly sets up the punchline by muttering "Uh-huh" in what I expect to be a distracted tone of voice.
Panel 4: When Liz asks her how she knew it was her, she goes into input failure because it either hasn't occurred to her that Liz has yet to learn the other meaning of the word "expecting" a child or she's wondering why she's raising a sitcom mutant child whose maturity fluctuates so as to meet the needs of the writer.
Summary: We're about to set off on a marvelous journey to the past wherein we get a reminder of why it is that Mike is always so angry and why he never seems to want to get along with Liz. She's as good at understanding that is she is remembering that her children weren't born forty and jaded like her.