In his article “The Homosexual Motif in Willa Cather’s ‘Paul’s Case’”, Larry Rubin argues that the primary reason behind Paul's inability to accept his reality, and the reason why he isolates himself from the others is because Paul is gay. Rubin attributes certain behaviors in which Paul indulges as supporting factors that set him apart from the rest. Some of the instances that he mentions include Paul's overly-fashionable style of dressing, his feminine need to dip his fingers in violet water and cover otherwise typical smell, and his unmeasurable love for extreme beauty.
Although being gay, according to Rubin, is a negative characteristic in Paul, it explains for the reason why Paul feels so different and unable to connect to the other males in Cordelia Street. Moreover, it could also be that Paul himself does not understand the aesthetic image he superimposes over everyone else, particularly his teachers. It is for this reason that Paul's teachers find his smile offensive, and the glance in his eyes unbecoming of a boy. Hence, it is the teachers at Paul's school who reject him first and most consistently, making him perhaps feel even more awkward and different.
Similarly, Claude Summers's "A Losing Game in the End": Aestheticism and Homosexuality in Cather's "Paul's Case" also offers that Paul represents the isolated male gay teenager who is socially alienated from a society that does not understand nor will ever understand him. The difference in Summers's study is that his study is based on Willa Cather's own exploration and acceptance of her sexual identity as a lesbian woman. For this reason, the isolation that she suffers growing up is reflected in Paul's own alienation from the rest of the world.