It's a combination of sillytalk (also anarchist praxis), and getting to the actual essence of the anarchist axiom: food is something we all need. One of the ways to solidify is through sharing hunted and gathered food. Canteens/foodbanks are a public place folks can combine all the gathered food, cook, serve, and commune with.
I am mocking the meme of “shopping” because that is capitalist praxis. Not the [food] cart itself, but the act of shopping. Returning say cooking utensils, washing tables, cleaning the floors, that is the true equivalence of the thesis of this meme.