I would say that the applicant who wrote the “Imagine” essay didn’t get due to the essay’s flat prose, poor organization, and questionable grammar, not its subject matter. The song was not sung “by the show,” but by the characters on the show. The sentence “When I watched this episode while the deaf adolescents were singing it, and soon joined by another glee club, it surprisingly affected me…” is just an incredible mess. He didn’t watch “while” they were singing; it should be “were joined by;” and “surprisingly affected me” is a terribly clumsy construction. How about: “As I watched another glee club join the deaf adolescents in singing the song during this episode, I was surprised by how much it affected me.” Not all applicants will be strong writers, but all need to show at least a basic grasp of how to communicate a thought.
The idea that core affect is but one component of the emotion led to a theory called “psychological construction.”  According to this theory, an emotional episode consists of a set of components, each of which is an ongoing process and none of which is necessary or sufficient for the emotion to be instantiated. The set of components is not fixed, either by human evolutionary history or by social norms and roles. Instead, the emotional episode is assembled at the moment of its occurrence to suit its specific circumstances. One implication is that all cases of, for example, fear are not identical but instead bear a family resemblance to one another.