Sensory details, as the term implies, convey information using the five senses: sight, sound, touch, taste, and smell.
"Silence" is repeated twice in the first paragraph. As he walks, Mr. Mead sees "dark windows" in the houses and cottages. If silence indicates that no one is out on the streets, dark windows are a desolate sign that nobody is at home—or, as we find out later, people are watching their viewscreens, cut off from other people.
Bradbury pictures Mr. Mead as a "lone figure" walking down the street.
A particularly vivid sensory image describes the deserted highways, comparing them to dried streams:
But now these highways, too, were like streams in a dry season, all stone and bed and moon radiance.
The police car that takes Mr. Mead away is empty. Mr. Mead's house is the only one lit up, emphasizing its isolation from its gray neighbors. In the last paragraph, Bradbury repeats the word "empty," describing empty streets and sidewalks once again, and uses the word "chill" in the last sentence, meaning both the chill of November weather and the chilly emotion one can feel when all alone.