Well, the third part of Eliot's Preludes seems to be addressing an unnamed "you" figure who's part of the neighborhood Eliot is decribing throughout the poem. The lines you've identified help us narrow down some possibilities about who this person may be. We know it's a woman, because she's taking the "papers" out of her hair. In the time period when Eliot was writing, women would often curl their hair at night into little scraps of paper known as curling papers. In the morning, then, they would uncurl these papers from their hair. This woman is trying to make the best of her appearance, to a certain extent. However, as she sits on the edge of the bed, we can see the hidden grime of her existence—her hands are "soiled" and the soles of her feet are "yellow," suggesting that she can't quite rise above the "sordid" circumstances in which she lives.

The fourth section of the poem brings in another unnamed person, a male whose "soul" is part of this neighborhood. It is "stretched" across the skies around this part of town and feels "trampled" by the passage of those people who flood through the neighborhood on their way home from work, reading newspapers. These people—or perhaps the man's soul itself—are "the conscience of a blackened street." They are the heart of what this neighborhood is.

Eliot then uses an "I" pronoun to say that he is "moved" to thoughts of his own by these images when he thinks about these people. He feels that there is "some infinitely gentle / Infinitely suffering thing" involved—that is, however dirty and soulless a neighborhood might seem, the dirtiest neighborhood is the scene of good people suffering.

At the end of the poem, he exhorts an unnamed "you" to wipe away these thoughts, perhaps, "and laugh" instead, remembering that things are always changing and yet are always the same; "the worlds revolve."