Personally I think the fragmented style of writing that Cisneros adopts has a great effect on the impact of this piece. There is a sense in which the style links to the theme of the vignette. We are given a series of fragments of sentences in a very broken style:
She met him at a dance. Pretty too, and young. Said he worked in a restaurant, but she can't remember which one. Geraldo. That's all. Green pants and Saturday shirt. Geraldo. That's what he told her.
Note that this broken style reflects the shock and disorientation of Marin in finding out that the man she had danced with just a few hours before had been killed. However, there is a sense in which this broken, incomplete style also reflects the incomplete picture we are given of Geraldo and his story. He is left unfinished, a hidden figure of whom we capture only vague glimpses. This relates to the central theme of the plight of migrant workers, who need to remain anonymous for their own safety.