How does Jim Carroll use imagery in The Basketball Diaries?

Imagery:

“It was a dream, not a nightmare, a beautiful dream I could never imagine in a thousand nods. There was a girl next to me who wasn't beautiful until she smiled and I felt that smile come at me in heat waves following, soaking through my body and out my finger tips in shafts of color and I knew somewhere in the world, somewhere, that there was love for me.”

“It was in Central Park near the lake and I watched a weeping willow turn into a giant rooster and fly off. No tree remained. It glided beautifully into the sky, a big blue barnyard. My mind went with it, something all you bald head generals and wheelchair senators could never imagine.”