The speaker uses intense imagery from start to finish, making the brutal murder horrifyingly visceral and immediate for readers. The stark, intense imagery emphasizes the horror of the racist violence depicted in the poem.
The poem starts with the speaker describing a seemingly peaceful "grassy clearing" on a sunny morning, making what comes next feel all the more shocking and horrible—like some perversion of this fresh, natural world. The speaker notes the "design of white bones" on "a cushion of ashes," for example, the "charred stump of a sapling," the "torn tree limbs," the "tiny veins of burnt leaves," and "a scorched coil of greasy hemp." Readers can immediately envision the remnants of a great fire and tell that something terrible has happened here.
The speaker evokes the scents of the scene as well, noting the toxic, "lingering smell of gasoline" that hangs in the morning air. The frank description of torn, bloody clothes and a crowd's trash helps the reader piece together the scene just as the speaker does—one of horrible torture turned into entertainment.
Other bone-chilling details make it easier for readers to really feel the speaker's fear. As the scene of the lynching overwhelms him, the sun suddenly goes dark and a "night wind mutter[s] in the grass and fumble[s] the leaves in the trees." The speaker describes not just the rustling sound of leaves but also the "hungry yelping of hounds" in the distance and "thirsty voices" that yell out from the surrounding "darkness."
As the poem goes on, the details get more and more gruesome and disturbing. Feeling his own body merge with that of the victim, the speaker says, "And my skin clung to the bubbling hot tar, falling from me in limp patches." The idea of skin fusing with "bubbling hot tar" is truly awful and sickening, as is the image of that skin falling off a person in "limp patches."
These excruciating descriptions are so intense that readers can almost understand why the speaker would experience relief when the mob pours gasoline on him—this, at least, "cool[s]" him down for a moment. But then the mob lights him on fire and his body goes up in a "blaze of red": another instance of visual imagery that makes it impossible for readers to overlook the speaker's staggering pain and trauma.