A unicorn's face belonging to a mythical creature in the form of a white horse with a long horn on its forehead. It's generally depicted as a white horse head facing left, with a pink mane and a rainbow horn.
This emoji may also refer to fantasy and unique nature of something.
Unicorn is often used for various content related to LGBT-community because of its resemblance with Gay Pride Flag. It's also commonly used to talk about start-ups which are sometimes called "unicorns".