In this proverb, "male sophomore" refers to male sophomore, while "perfect appearance" refers to appropriateness, propriety and charm. This sentence expresses the second year of college. Boys are in their youth and prime of life, and they are often attractive and popular. This is related to the maturity of age, the growth of self-confidence, academic and social development. "Sophomore boys are handsome" is often used to describe that boys are widely welcomed and loved at this particular age.