How does Stephen King use imagery in Nightmares & Dreamscapes?

Imagery:

"The snakes in pissant little roadside menageries like this one couldn't kill you; their venom was milked twice a week and sold to clinics that made drugs with it."

"Howard uttered a deep and primitive howl - a sound such as had never before escaped his polite set of CPA vocal cords - and flailed at the edge of the door."