This context is from The Children's Bach by Helen Garner
They all walked out on the summer afternoon. The men took Arthur to bowl and bat, deep in the park near the drinking fountain, but the women kept going, with Billy between them, as far as the big cemetery and in through the turnstile. Billy’s hands sweated in theirs. Inside the railings the world opened out. The horizon widened and dropped away, and the sky rose until there was nothing above them but dry air: they crept along a plateau that tilted slightly to the southeast, in which direction lay many suburbs and a low mountain, very far.
Mrs Fox’s discourse ceased while she took account of this immensity of air, lowness of ground, distantness of landmarks. Then it began again, and wound on and on through the afternoon, stupefying in its pointlessness and yet as soothing, as voluptuous as the murmuring of a dressmaker, the warmhanded whisperer who kneels in contemplation before the hem, who pats and strokes, bunches and gathers, in whose presence nothing is required but perfect passivity.
In the sentence "Then it began again, and wound on and on" does it refer to "Mrs Fox’s discourse" and mean "Mrs Fox’s discourse began again and wound on and on"? (wound= past tense of wind and it is used methaphorical meaning "her speech was confusing")
And does the rest of the part in bold mean: her pointlessness speech was confusing but still soothing and voluptuous like the murmuring of a dressmaker when she is sewing the hem with careful attention and pats and strokes the clothes and bunches and gathers them. In presence of ones who she should only do their orders and nothing else is needed?
I wanted to know if I understand the whole part in bold correctly. But the last sentence "in whose presence nothing is required but perfect passivity." is really unclear to me.