She is very disappointed, he accuses her of being light-minded, and she explains it's not the musical she appreciates so much as its effect on him.
Elaine: Musicals somehow have a humanizing affect on you. After a serious play we join the proletariat in the subway and I listen to a lecture on the drama. After a musical you bring me home in a taxi and you make a few passes.
Mortimer: Now wait a minute, darling, that's a very inaccurate piece of reporting.
Elaine: Oh, I will admit that after the Behrman play you told me I had authentic beauty -- and that's a hell of a thing to say to a girl. It wasn't until after our first musical you told me I had nice legs. And I have too.
This sprang to mind from the dark recesses of memory (recalled from back when I could credibly play the ingenue) because we happen to have seen two plays in quick succession in the past few weeks. After Henry IV part 2 we went straight home and Mr. W.
I don't remember Aristotle touching on this in the Poetics.