A dancer is a professional dancer. In Jolin's song, a series of lyrics such as "Spinning and jumping, I won't stop" all reflect the dancers' hard work of dancing day and night. However, their joys and sorrows are not necessarily seen by people, and no one will find or care about their joys and sorrows.
A dancer in India means yes. This is what the so-called "magic self-energy, dancing gorgeous life" means.