How does Wally Lamb use imagery in I Know This Much Is True?

Imagery:

"The orthopedic surgeon who later treated my brother was amazed at his determination: the severity of the pain, he said, should have aborted his mission midway. With his left hand, Thomas enacted each of the steps he'd rehearsed in his mind. Slicing at the point of the right wrist, he crunched through the bone, amputating his hand cleanly with the sharp knife. With a loud grunt, he flung the severed hand halfway across the library floor. Then he reached into his wound and yanked at the spurting ulna and radial artery, pinching and twisting it closed as best he could. He raised his arm in the air to slow the bleeding."

"She cocked her head just like that wooden bird on her desk."