Like most of the other characters in the novel, José is interesting because of what he can tell us about Holly. When Fred dies and Holly has to change her future plans, she seems to really enjoy acting as José's wife. She cooks for him, mends his clothes, and takes his suits to the cleaners. She also seems truly happy when she thinks she'll be moving to Brazil to start her family with him.
José's presence in Holly's life (and the stability he represents for her) reveals to us that perhaps her crazy life isn't as fulfilling as she wants everyone to believe. For a brief period of time, José offers Holly the chance to feel settled, to feel like she finally belongs somewhere, and to feel like she no longer has to go to Tiffany's when she's having the "mean reds." And when he leaves her because he's too much of a "coward" (17.8) to be associated with her after the arrest, she's truly sad because she really "did love him" (17.13). José is one of the rare characters in the novel who has an actual impact on Holly, who has the ability to both make her happy and to upset her, and we think this makes him quite worthy of consideration since so few people have this power.