The slight change in the repetition -- from "here" to "now" -- and the redirection of the remark from "the uproar" to Antonia, serve to accentuate that he is leaving idealism; i.e., his ambitions are no longer about rehabilitating or regenerating society. At this news Antonia removes her veil, as if in surprise or to speak, and in so doing uncovers what we might call the true "face" of idealism to Charles Gould, who in the next chapter has succumbed to total revulsion over the "cruel futility of things."
Allegorically, it is materialism as such which leaves idealism here. Industrial
progress has burned out; it has crossed the historical line and can no longer
pretend to be the means whereby mankind will save itself, as earlier it could.
Note that socialism immediately enters the scene, complete with spurs of conquest:
it is ready to assume the vacated idealistic leadership of the world and be
the next passionate ideal by which mankind hopes to save itself. In the sequence
that follows, idealism, before lowering its veil again, negotiates and completes
the allegorical transfer of power.