She's bearing down on the sheet music, she's been playing a long time. It is a good way to work off tension, I'm sure too.
For some reason that pic puts me in mind of the Godfather movie where Michael is getting his son Baptized, meanwhile the hits are being made that changed the balance of power.
Of course the real reason for this symbolism is the tweak the hell out of the male chauvinist states of Iran and the rest and remind their women of how much more our women get. I'm pretty sure this is intended for effect. Good for us.