What does Mercutio think about the nurse when she appears at the end of act 2, scene 4?

In act 2, scene 4, the Nurse visits Romeo, acting as an intermediary for Juliet to attain more information about when Romeo plans on meeting her again. When the Nurse arrives on the scene, Mercutio completely disrespects her by hurling merciless insults at her to entertain himself. Mercutio begins by begging Peter to give the Nurse a fan so that she can hide her ugly face. Mercutio then proceeds to use sexual innuendos to insult the Nurse and even refers to her as an old, ugly prostitute.
He also compares the Nurse to stale rabbit meat—which he states is okay to eat if you can't find anything fresher. Mercutio's insulting, demeaning treatment of the Nurse reveals his extremely low opinion of her. Mercutio recognizes that she is not considered nobility and takes pleasure in upsetting her. After Mercutio leaves the scene, Romeo tells the Nurse that Mercutio is simply a gentleman who loves to hear himself talk.

At the end of Act 2, scene 4, Mercutio badmouths the nurse with impunity, calling her ugly and mocking her appearance with relish. He seems to be entertaining himself with his own rudeness towards the nurse, and his jokes understandably infuriate the nurse. She criticizes Peter for not coming to her defense and wastes time expressing her anger before talking with Romeo about Juliet, who wants to give Romeo a message; this message is the whole point of her confrontation with these young men. Romeo attempts to calm the nurse by describing Mercutio as a man who "loves to hear himself talk" but the nurse is too upset by Mercutio's words to be comforted by this explanation, and she goes on to warn Romeo not to toy with young Juliet.