In John Updike's "A & P," we find a world within a world, or a microcosm. The supermarket is a small world where people come and go, where there are rules, and where adult and youngsters are present. It is a place, also, where Sammy takes a big step towards growing up.
Sammy notices the girls when they enter: they could represent a variety of different kinds of young females, except one is obviously a leader. Sammy describes her as queen-like, as she walks down the aisles.
Sammy and his friend are typical boys: their attention is completely focused on the girls when they enter, wearing bathing suits.
The supermarket seems like its own world with aisles like roads; air conditioning provides relief from the summer heat, but the doors that keep it in are also the doors that create the boundaries of this small world; and, there are rules that define the behaviors of those who enter, much the way the world at large does.
When the girls reach the front, the manager chastises them for wearing inappropriate attire while in the store. The "leader" of the group argues that they only wanted one small item, but the manager insists that they follow the rules.
Sammy is compelled to speak up for the girls, feeling that perhaps the rules are too harsh (and, of course, he is enchanted by the "queen.") This is similar to people who speak out against the establishment when they feel something is unfair or censorship is unwarranted.
As in every day affairs, Sammy decides that he must choose to conform or leave; on principle, he decides he must remove himself from this "society," and he quits he job. The manager tells him he may be sorry, and Sammy believes this may be true, but he also sees the world around him more clearly, and there is no turning back.
In these ways, the supermarket is like a small world with those who inhabit it: rules that must be obeyed, and there are people who see the need to change the world and cannot reverse course once they have perceived the world in a new light.
Updike's "A&P" is an effective story because the author had the good sense to create a settiing which every reader is familiar with. By doing that, Updike makes his task much easier and also makes it much easier for the reader to visualize the setting. Everybody knows what the inside of a supermarket looks like. There are long rows of shelves holding cans, cartons, and all the other things supermarkets carry. In front are the checkout counters, and these look about the same in supermarkets all across America. Everybody knows what the shoppers look like as they push their little carts around, stopping and starting. Everybody knows what the canned music over the loudspeakers sounds like. The customers look as much like sleepwalkers as they do like "sheep." Everybody knows what supermarket managers look like, what sort of clothes they wear, and how they stand and watch and how they talk. And, of course, everybody knows what coltish young girls in bathing suits look like. It is easy to imagine three of them entering a supermarket and looking bashful and shy but trying to be more poised then they feel. "A&P" teaches a good lesson to aspiring writers. It is easy to get readers to visualize what they have already seen. Another good lesson has to do with contrast. The girls stand out because of the setting much more than they would if they were merely walking along the beach. "A&P" is a microcosm of society mainly because everybody has to eat, and therefore most of society will pass through supermarkets. John Updike makes readers aware of the beauty and drama of an ordinary supermarket. Updike studied to be a painter before he became a writer. His stories often show his visual sensitivity. There is a little drama in "A&P," but mainly it is a picture of a supermarket in a small town. Sammy, the narrator, exits--and the reader exits with him.