There is no convoluted plot and nothing special in terms of characters in this story by Porter. The protagonist is a woman who is good-looking, perhaps capable and appears to be independent. That's not enough to make Theft a good piece of literature.
We meet the protagonist when she leaves her apartment in New York on a rainy evening. That evening, we also meet her suitors. First she met her beau Camilo, who loves to pay for her outings; her refusal to pay gave the impression of an independent woman. Then she met her ex-lover, who wanted to settle down with another woman. When he tells her this, she remains cool and indifferent. Then we and she met another man of hers who is in debt and whom she is helping as his girlfriend. The next morning we meet her janitor, so we can deduce that she is a middle class woman. The cleaner has plundered her purse and then given it back to the protagonist. That's the whole plot of the short story titled Theft by Katherine Anne Porter, a Pulitzer Prize winner. At first glance, it seems like a trivial plot and a trivial protagonist, but Porter's Theft is a pretty strong short story. Ann Porter offers a 24-hour journey into the mind of a so-called independent and strong woman. During this chain of events, which only take place in these 24 hours, Porter creates the portrait of a tragic hero: a woman who is lost.
Let’s retrace the chain of events, but let us think about the symbolic aspects.
The encounter with Mr. Camilo left the protagonist drenched, which can symbolize the weakness of the woman: First she lost her strength, then she deprived herself of relationships with men, and finally she let her friend steal from her. Not literally, but he did not give her the money he owed her. And she does not even object when he tries to tell her that his priorities are more important than hers. To make matters worse, she was actually robbed the next day. This situation has taken away everything she believed in. She was used to trusting people, and she prided herself on sleeping with her doors open and never being robbed. You may think that she will feel less disillusioned when the janitor returns her wallet. Not really. The turn of events had a catastrophic effect on her.
Now she is a thief. She steals from younger women. It's because the janitor stole her wallet for her teenage niece, and now she wants it back from the janitor's innocent niece. She realized the tragedy of her life. She began to perceive herself through the prism of a weak middle-age woman and a sexual object. The returned beautiful porteille symbolizes this. The janitor's niece does not need gimmicks like beautiful porteilles, because her beauty does not need accessories, says the janitor.
And yes, she is the tragic protagonist, the creator of her superficial life.
She has deceived and stolen from herself. She has let herself get soaked, betrayed her love and robbed herself of friendships.