'Bony mules hitched to Hoover carts flicked flies in the sweltering shade of the live oaks on the square. Men's stiff collars wilted by nine in the morning. Ladies bathed before noon, after their three o'clock naps, and by nightfall were like soft tea-cakes with frostings of sweat and sweet talcum.' - What (or who) is described metaphorically in this passage from Harper Lee's To Kill a Mockingbird?

A metaphor states that one thing is something else. This description, however, is too simple for the way metaphors often work in poetry, literature and speeches. You will often find something being described, or written about, as if it is something else, without the writer ever saying 'x is y' (do you see the mathematical metaphor there?).