It is interesting that although Sammy is the first-person narrator of this excellent short story, we only find out his name when he quits at the end of the tale. We know that Sammy is working as a checkout clerk in an A & P supermarket. It is important to focus on his language and how we are able to tell a lot about his character through his speech. He is clearly young, being nineteen, as he speaks in a kind of vernacular slang:
She was a chunky kid, with a good tan and a sweet broad soft-looking can with those two crescents of white just under it, where the sun never seems to hit, at the top of the backs of her legs.
It is interesting that his character seems to vacillate between apathetic cynicism of those around him and a kind of romantic sensibility that draws him to the girls in the supermarket. Note how he refers to the "cash-register-watcher" he is serving:
...a witch about fifty with rouge on her cheekbones and no eyebrows, and I know it made her day to trip me up. She'd been watching cash registers for fifty years and probably never seen a mistake before.
And yet, in spite of this humorous cynicism and references to "freeloaders" and the "bum" in the store, he is greatly impacted by Queenie. Watching the way that the manager Lengel embarrasses them makes him want to commit an act of defiance against the strictness of society and "policy." Although he tries to be a hero, his gesture goes largely unnoticed. Although he tries to find the girls, they are long gone, and as he leaves, he suddenly has an insight into "how hard the world was going to be to me hereafter" if he continues to challenge the strict order of society as he has just done.
Thus we can say that Sammy is a young man who oscillates between funny, cynical views and romantic sensibilities. He shows empathy for the girls and the way they are treated, and through quitting his job comes to an understanding of what it is to defy society.