How does Alison Lurie use imagery in Foreign Affairs?

Imagery:

It was just nonsense off the top of her head, a way of focusing attention on herself or changing the topic of conversation, perhaps-a musical noise, that was all. Words don't matter to actors as they do to a literary person. For them meaning is mainly in expression and gesture; the text is just the libretto, a line of empty glasses that the performer can fill with the golden or silver or bronze liquid of his or her voice.