The context is that Cholly is having sex with Darlene, and during the act two white men appear, one of whom carries a flashlight, and he puts the light on Darlene and Cholly. They are terrified, and then the white man with the flashlight, whom Cholly begins to know only by his flashlight, tells them to keep doing it so they, the white men, can watch, in this way humiliating both Cholly and Darlene. Cholly pretends to have sex under the light of the flashlight, but is too terrified to perform.  This causes him to hate Darlene, transferring all of his humiliation and hate of the men to her.  At this moment "the flashlight" becomes a metaphor for him being raped by the white men: "the flashlight wormed its way into his guts" even while he wants to do it "lard, long, and painfully" to Darlene. The muscadine is the wine he drank earlier, which now turns rotten ("fetid bile") in his stomach. When they finish, her hands "look like baby claws," this simile showing again that he sees her as a predator on him while at the same time realizing she is as much as a victim as he.