The girl is supposed to live in a boring, black-and-white world. One day, she finds a mysterious mirror on a bench. In the mirror, she sees a colorful flower that does not exist in her world. The mirror in the episode reflects the protagonist's heart, and the colorful flower brings color to the girl's world.
Through the mirror, the girl discovers that being different and standing out is okay. How things are is about how you look at the perspective. Seeing things differently produces different results. The perspective of how you look at things determines what you want and who you want to be. Ultimately, the girl broke away from the ordinary world and became herself. She found her path.