The Lion Rampant flag is believed to have originated from King William I, "The Lion of Scotland".

Hopefully, the Rampant Lion will disappear soon from Celtic festivals and other displays, as it is much too "Sassanach" nowadays. And I note, in passing, that the UK flag or "Union Jack" is also on the eclipse, as most modern Scots prefer to emphasize their unique identity after devolution at the turn of the century.
Devolution does not necessarily equal full-blown independence, old boy. At present, Scotland is still a member of the United Kingdom of Great Britain and Northern Ireland, so there is nothing "incorrect" about a Union flag flying at a Scottish event.

T.