Excerpted from the site sparknote:

Amidst the callousness and exploitation, moments of compassion are few and far between, **although perhaps all the more significant for being so rare**. Even though he is taken in only grudgingly, the old man eventually becomes part of Pelayo and Elisenda’s household. By the time the old man finally flies into the sunset, Elisenda, for all her fussing, 

I couldn't make heads or tails of the bold part not only semantically also analyctically to analyse the part(grammatically).