Star
The Star is the most prominent symbol in the text. Stars are often used to describe something magical of special and that is exactly how they are used in this text. The Sneetches with the star are deemed more special than the others.
Star-off Sneetches
The Sneetches without stars symbolize a socially disadvantaged group of people. They are treated far worse than the other Sneetches and are often ostracized and treated badly by the others.
Star-on Sneetches
The Sneetches with the stars represent a more elite and superior group. They are very entitled and believe that the star gives them a special authority over the Sneetches without.
Sylvester McBean
He is depicted as a very intelligent and opportunistic individual. Indeed he may represent big corporations who take advantage of situations in order to make money. His greed has no bound as he offers new services to whoever needs it.
Star machine
The star machine can be a reference to the modern cosmetic industry. Many of the youth believe that changing the exterior will improve they interior and how they feel about themselves. Of course at the end the Star machine did nothing to help the Sneetches and they realized that they had to change their own attitudes before changing themselves superficially.