How does Fawn M. Brodie use imagery in No Man Knows My History: The Life of Joseph Smith?

Imagery:

The eight-year old Joseph seemed to recover well enough, though slowly, until one day Lucy was terrified to discover huge infections breaking out upon his shoulder and leg. Herb poultices were as unavailing as the usual prayers, and Lucy finally called in a physician. He bled the boy, plied him with purges, and probed his ugly sores. When the leg infection refused to heal, he talked of amputation, but Lucy fought against the saw and knife with a fury that annoyed but checked the barber surgeon. He had to content himself with chiseling out a piece of bone below the child's knee. When the savage operation began, Joseph would not let himself be tied to the bed, nor could the father force whiskey between his lips to stifle the pain. He screamed to his mother to leave the room, lest she should more than he.

They stripped him, scratched and beat him with savage pleasure, and smeared his bleeding body with tar from head to foot. Ripping a pillow into shreds, they plastered him with feathers....Johnson had to be content with seeing the prophet beaten senseless. Rigdon likewise was beaten and dragged into unconsciousness over the frozen ground.

After a time Joseph sat up and began to tear at the tar which filled his mouth. His lips were bleeding from a glass vial that he had crushed between his teeth when someone tried to force it down his throat. He made his way back to the house stiff with cold and pain. Emma opened the door. In the half light the great blotches of tar on his naked body looked to her like blood and she fainted on the doorstep.