The Question and Answer section for A View From the Bridge is a great resource to ask questions, find answers, and discuss the novel.
There is tension starting to mount with the arrival of the two brothers. Catherine clearly fancies Rodolpho, and he feels the same way. Eddie loathes this union as he sees Catherine starting to slip from his grasp.
The effect of having Alfieri as the narrator enables the author to communicate an objective view of the action. Alfieri has very little effect on the movement of the plot, he's an observer above all else, but he also provides an all around...
I think this is more an opinion question for you rather that me. Isolate what writing you are referring to first and then consider how Catherine had changed.