Final answer:
Dramatic irony in the play arises from Vicky and Gomez's unawareness that the party is a no costume event, which creates humor when they enthusiastically plan to win a costume award.
Step-by-step explanation:
Dramatic irony is used in the play to create humor based on what Vicky and Gomez wear. Despite being informed by Selena about the party being a no costume event, in order to honor their Granny who is in the hospital, Vicky and Gomez show great enthusiasm for their costumes, believing they will win a costume award. The audience is aware of the fact that they are mistakenly preparing for a costume party, leading to a humorous situation when they arrive in their elaborate outfits.