Neni giving away her books
Neni gives away her pharmacy textbooks after the family moves back to Cameroon. This is a symbol of her giving up her freedom and education after leaving the U.S., because while she was studying to be a pharmacist in America, this dream is not accessible to her in Cameroon, and so she has to give it up. The act of giving away the books symbolizes Neni giving up on the life she imagined for herself.
Vince Edwards
Vince is an allegory for wealthy white liberals who see themselves as enlightened, but in reality are clouded by their own privilege. He critiques his parents and their spending habits, wants to go abroad to enlighten himself, and critiques Jende's view of the American dream. He thinks of himself as an awakened liberal that understands the ways of the world, but in reality, he benefits from his parents' wealth (in the form of tuition, vacation, etc.), and is just as much a part of the system as his parents.
Jende's mother's death
Jende's mother dies while he is in America and he cannot go home to bury her. This loss devastates him and acts as a symbol for the difficulties of being an immigrant far from home. Her death makes him realize how much he is missing by being far away from home, symbolizing all of the immigrants who miss deaths, births, and other major family events. This is the event that starts spurring him towards leaving America.
The car
The car Jende drives the Edwards family around in acts as a symbol for the class lines that divide them. While they spend time together in the car (often for a full working day), the lines between them are always drawn, because Jende is an employee given orders by his employer. They may spend time together, but the car (and the different rows they sit in) symbolizes how the class lines between them will always remain in place.
Neni's picture of Cindy
The picture that Neni takes of Cindy in the Hamptons is a symbol for the small amount of power that she latches onto. While Neni has the picture of Cindy during her drug overdose, she can blackmail her. Since Neni is a woman of color whose husband is employed by the Edwards's, she has very little power, and the photo is a symbol of the small amount of power she does have.