This particular Sunday edit by Gallagher is pretty inscrutable to me. It's clear that he's left the ice cream shop with his ice cream. He tastes it. Is shocked by it. And then I'm not sure what happens. Since the trash can isn't shown before that, I have to assume it's spontaneously manifested. Maybe it was the shock of licking an ice cream and finding it tastes like yourself? But in theory you should taste nothing when you taste yourself. So I have zero idea what is going on.

But then maybe he tasted it. Didn't kike the flavor of himself, rage tossed a trash can, made the best of things by finding a fish carcass to eat instead of the ice cream?

The last panel of a Sunday edition is always the author telling us about some cat that a reader told him about. In this case someone got a cat born in a junk yard on an American holiday and that cat has a lot of attitude.