How does David Morrell use imagery in First Blood?

Example of Imagery:

"It was the same jungle camp they had tortured him in, the same thatched huts and rich green mountains. For a reason he did not at first understand, they had treated his wounds while he was unconscious: the slashes in his chest where the officer had repeatedly punctured him with a slender knife and drawn the blade across, grating against his ribs: the lacerations on his back where the officer had crept up behind, suddenly lashing."