Hair—braided chestnut, coiled like a lyncher's rope, (1-2)
The long chestnut hair is good evidence that the person described is a white woman, but an argument can be made that the poem is merging the male victim and a female. In any case, it's clear from the get-go that this speaker is interested in how things look—not how this figure feels.
This is by far the shortest and strangest image in the whole poem. It's just two words, and yet somehow, Toomer has managed to pack in a number of possible meanings. "Fagots" are bundles of sticks, often used for burning. So if we're just talking appearances here, this figure's eyes look on fire. But the word itself also means "death by fire," which alludes to a whole tradition of fiery deaths throughout world history. But it also alludes to the fact that many lynching victims were set on fire as they were hanged. And all that meaning is contained within this woman's eyes. So yeah, we'd say there's more than meets the eye here (insert groan).
Lips—old scars, or the first red blisters, (4)
The "first red blisters" bit is a little confusing, but it could refer to how skin blisters when burned, which would fit in nicely with the image in line 3. In some ways, it's a shocking comparison. We could see how eyes could be described as "fagots," as if they're afire with passion. But lips as scars or blisters? Yeah, that's not exactly a flattering metaphor.
And her slim body, white as the ash of black flesh after flame. (6-7)
Whew. What a doozy of a line, right? In the final moment of the poem, we learn what's really going on as Toomer merges the appearance of a white woman with that of a black corpse. Until now, we've only been able to guess at what he was getting at. But now we've got the goods. And it's an interesting moment of racial harmony, in a strange way. After all, by describing this woman in terms of a black lynching victim, Toomer manages to show us (in a gruesome way, of course), that we're not all that different looking to begin with.