Why does the speaker of the love song of j alfred prufrock tell us more than once that the woman come and go talking of michelangelo?

He repeats the same lines first of all to show that women are superficial in a way - they talk about art and Michelangelo without actually knowing anything about it, they just want to sound smart. Second of all, he wants to point out how these conversations are repetitive - there isn't much to say about the topic, so they just repeat what they had already said about it.

Sure but what’s your question?