The phrase "unique appearance" refers to something that stands out or is distinctive in its appearance. It means having a style, look or design that is different from anything else and cannot be mistaken for any other thing. This could refer to an individual's physical characteristics such as their hair color, facial features or body shape; it can also describe the way someone dresses or carries themselves, which sets them apart from others. In short, a unique appearance means being one-of-a-kind and having something that makes you stand out in a crowd.