The stubbornly idealistic Giorgio is associated with Higuerota, symbol of the pure Ideal. Mrs Gould's "thirst" is for more than water; it is for Giorgio's reassuring commitment to his dream-ideal. However, Giorgio has just bared his head to the sun -- he too is about to experience disillusionment.
This seems a good place to note that Antonia is not associated with
Higuerota, in this or any other scene. There is a firm distinction in the novel
between the Ideal, symbolized by Higuerota, and idealism, allegorized
in Antonia. Antonia represents and advocates no vision of utopia, but the fight
to get there, the fight itself whether or not it will ever be successful. (In
the next chapter she will make this clear.) The novel's symbol for idealism
is not the mountain but the eclipsing substance, such as cloud and mist, and
fittingly Antonia is often portrayed as being behind a screen, be it a veil,
a fan, or even her long eyelashes.