How would you explain ‘the increments of dust’ in the context?
The excavation lay open: a mass grave, protected under a temporary tin roof set on posts. Down a few dirt steps, there they were, skeletons of men lying in a row like fish in a box, their narrow, dust-colored bones only faintly lighter than the reddish dirt in which they were embedded. Oddly, the skeletons were perfectly flattened, as if all these humans had been pressed under a hot iron. It took a moment for the eye to adjust to the increments of dust, discerning the human from nonhuman elements.
How would you explain ‘the increments of dust’ in the context?
Thanks!
PS: It’s from The Lacuna by Kingsolver.