The move used had recoil and no charge turn that I could see.Actually, I don't know if Swana learns Brave Bird, but it was confirmed it learns Sky Attack, so I bet that's it.
Though I can't read Japanese I can match symbols (lol).
The text at the bottom of the video at 0:27 looks an awful lot like ブレイブバード which is Brave Bird's Japanese name according to Bulbapedia.
So I'm going to say Swanna knows Brave Bird.
The name for Sky Attack is actually quite close (God Bird: ゴッドバード ) so maybe there was some mixup or it learns that as well.
Either way it's good news because Sky Attack has sucked since Gen I whereas Brave Bird is one of the best Flying type attacks in the game.
EDIT: First Water/Flying to learn a single turn physical Flying attack greater than base 60 power? w00t!