In the Red Badge of Courage what sight horrified Henry as he entered a "Chapel" made of pine boughs?

From the text:

"He was being looked at by a dead man who was seated with his back against a column like tree. The corpse was dressed in a uniform that once had been blue, but was now faded to a melancholy shade of green. The eyes, staring at the youth, had changed to the dull hue to be seen on the side of a dead fish. The mouth was open. Its red had changed to an appalling yellow. Over the gray skin of the face ran little ants. One was trundling some sort of a bundle along the

upper lip."