This almost religious description, in which Nostromo ascends a staircase toward a "bright light," to find Teresa upon a "couch of state," overtly suggests an allegorical role for Teresa in the book. I believe that Teresa represents nothing less than the material promise of America for the common man. "Padrona," as she is referred to here with a capital letter, like a title, is Italian for "landlady," and her guiding motivation, as we learn in this scene, is to provide materially for her children. To this end she "encouraged" Nostromo (the People) to come ashore in America, specifically to "make his fortune" , and the image of the sailor stepping ashore is deliberately repeated here. The Padrona's "physical anxiety and unrest" is, we learn, not merely a reflection of her illness, but of her frustrated ambition for Nostromo to physically better his condition. Note that except for the first and last words of the paragraph, the two characters are referred to by capitalized, generic titles ("Capataz de Cargadores," "Mediterranean sailor," "Padrona"), emphasizing the generic, allegorical meaning.
The dialogue that follows pits material welfare against integrity of character
in a war over the meaning of the word "treasure." Nostromo defends
his trustworthy reputation as a "treasure," while Teresa denigrates
it as mere "fine words" and urges Nostromo to "get riches."
By failing Teresa's "supreme test" (and choosing his mission to save
the silver), Nostromo retains the "treasure" of his integrity, but
Teresa leaves him with a devilish curse of "poverty" that can be interpreted
to apply to either kind of wealth. Allegorically, we are left with the dilemma
that for the People to be rich in integrity, they must be poor in material welfare,
and vice versa.