How does Caroline Knapp use imagery in Drinking: A Love Story?

Example of Imagery:

"Craziness, dark secrets, alcoholic furies, that's how you become an alcoholic, right? It's encoded in your DNA, embedded in your history, the product of some wild familial aberration. There was always an undercurrent of moral failing in the stories I heard about alcoholics: they were unstable, unwell, irresponsible, and if they were parents, they tore through the lives of their children like tornadoes, drinking and divorcing, screaming and raging."