In "Gravity", by Judith Ortiz Cofer, the narrator's mother most likely put the guardian angel picture up outside the narrator's room c. to remind the narrator of her Puerto Rican roots.
Elenita starts the narration speaking about her bedroom, which is decorated following her style with her books, and her radio. Her mother decorated the house with pictures of saints and angels in what Elenita calls a primitive Puerto Rican style. Elenita took the picture of the guardian angel out of her room. Her mother placed it outside her door so that she sees it every time she goes in or out of her bedroom, to be reminded of her Puerto Rican roots.