Flight attendants have a God-complex. They get their kicks arresting customers and/or throwing them off planes (who then get comped by the airline). I’ve seen it happen to others who may(!) have given the attendant a dirty look.
It happened to me once for complaining when I was thrown out of first class (which I’d paid for). After 15 years, I still remember the bitch’s name...
I don’t deny that SOME (but not most)FA’s become power mad and abuse passengers.
However, this does not seem to be one of those cases. Painting one’s nails in airline cabin is horrendously rude to the other passengers, and poses some level of safety risk, and there is probably a rule against it.
The FA asked the woman to stop, but then she snuck into the bathroom and continued. I think they were too easy on her. She should have been ejected from the plane, at 30,000 feet. :)