The following text is from Herman Melville's 1854 novel The Lightning-rod Man.

The stranger still stood in the exact middle of the cottage, where he had first planted himself. His singularity impelled a closer scrutiny, A lean, gloomy figure. Hair dark and lank, mattedly streaked over his brow. His sunken pitfalls of eyes were ringed by indigo halos, and played with an innocuous sort of lightning: the gleam without the bolt. The whole man was dripping. He stood in a puddle on the bare oak floor: his strange walking-stick vertically resting at his side.

Which choice best states the function of the underlined sentence in the overall structure of the text?