How does John le Carre use imagery in Tinker, Tailor, Soldier, Spy?

Imagery:

"'That's the point, isn't it?' Lacon observed quickly. His strength was improbable, Smiley reflected. One minute he was like a thin, drooping boxer whose gloves were too big for his wrists; the next he had reached out and rocked you against the ropes, and was surveying you with Christian compassion."

"All his awareness was behind him, fixed on the black revolver and the bands of chamois leather; on the pen-tops that turned to bullets as Jim threaded them methodically into the chamber, his lined face tipped towards the lamplight, pale and slightly squinting in the dazzle."