In this passage from Henry David Thoreau's Walden, the narrator uses strong sensory language to create clear images - to, in essence, paint a clear picture in words - of the forest and the hills. The narrator is able, through the use of such strong sensory language and imagery to give the read a clear image of what he is describing, which, in turns, makes the scene he is describing come to life.
Yes, it means someone feels very sad suddenly.
