That actually works in meetings or other group situations when people seem ignore my points - deeper voice works better. Not sure why doing it would be shocking. It is tiring to do it all the time through. Men chage their voices based on social situations too.

It works also with students when you are teaching.

I am pretty sure she also carefully selected cloths and hair style to project the right image and thought in advance about what she is going to say. It is the same thing. That is what all charizmatic leaders, whether good or bad, do all the time.