What makes Brooklyn an interesting read is not its sociology or historic background -- though these are well done and support the story effectively. It's the portrayal of an ordinary young woman, Eilis, and how she feels about a life that seems to be happening to her without her consent. She suffers from the sense that in her old life in Ireland and her new life in America she's really two different people. This is explicitly mentioned when she returns home to visit her mother, and looses a sense of what she had been doing in Brooklyn.
Eilis struggles to assert her own opinions, but is bullied by strong-minded women such as her employer in Ireland and her landlady in the US. She often ends up just fearing that she's acted inappropriately. The many connections between her relatives, friends, and neighbors create enormous pressure -- someone always seems to be reporting whatever she does. She tries to fit in, and with coaching from friends succeeds in dressing and acting like her peers -- these efforts are particularly described in the context of a dance in Ireland and one given by the church in Brooklyn, organized by Father Flood, her sponsor who organizes her immigration, her American job, her boarding house, and her school fees. But she's always in some way outside herself, observing but not quite fully participating, and often feeling that her real self is being defeated or disabled.
Her visit to the home of her Italian-American boyfriend points up the unacknowledged conflict that she's experiencing. Her reaction to the food she's served is emblematic of her reaction to the unfamiliar life in America. She had, as usual, been coached by a girlfriend before going into an unfamiliar experience -- in this case, her friend Diana had instructed her "about how to eat spaghetti properly using a fork only."
The boyfriend's mother's spaghetti, though was
"not as thin and slippery as the spaghetti Diana had made for her. The sauce was just as red, but was filled with flavours that she had never sampled before. It was, she thought, almost sweet. Every time she tasted it, she had to stop and hold it in her mouth, wondering what ingredients had gone into it. She wondered if the others, so used to this food, were being careful not to look at her too closely or make any comment as she attempted to eat it using only a fork as they did." (p. 154)The main course was similarly familiar looking, but unfamiliar inside:
"a flat piece of fried meat covered in a thin coating of batter. When Eilis tasted it, she found that there was cheese and then ham inside the batter. She could not identify the meat. And the batter itself was so crisp and full of flavour that, once more, each time she took a taste, she could not work out what had been used to make it." (p. 155)Dessert, "a sort of cake, Eilis thought, filled with cream and then soaked in some sort of alcohol" and thick, bitter coffee served in tiny cups, were equally unfamiliar despite a recognizable appearance. In a way, this was how she observed many of the experiences both at home and in her new country.