Panel 1: We don't get to see Brian asked if he's channeling a forty year old woman like we should because Elly yells for Mike to come inside for supper.
Panel 2: We then get reminded of Elly's faulty ability to prioritize when she gives him a list of chores to do before he sits down: hang up his coat, wash his hands and feed Farley before he sits down.
I think it fair to warn people at this point that even then, I wondered why she didn't assign him chores instead of just kicking him outside to stand around idle and frustrated. He'd still be busy and frustrated but at least he wouldn't be standing around understimulated. Letting him stand outside getting bored only to hand him chores when he's about to eat is just stupid.
Panel 3: In any event, she sets up the stupid punchline by telling him that the dog food is on the counter and help himself to the casserole. He says "Okay" as he puts his jacket away.
Panel 4: Since he remembers how terrible a cook she is because she won't cook regular food people like, he irritates her by asking if he will be able to tell her cooking from Alpo.
Summary: The wiseass in me wants to say that the dog food will taste better and be less salty. The normal person in me remembers that Elly would have been a lot better off if she would not conduct culinary experiments and stick to everyday foods her family actually looks forward to eating.