The way her hand holding the phone is shaking suggests she is in a real state of rage. This person needs serious help.
Thing is, if I were suddenly confronted with something I found intolerable, I might have a fit of my own. But there's a difference that we tend to avoid relying on, even though it actually applies here: she is in the wrong. She may think what she sees is something to condemn. But she is wrong.
She has no right to act this way, because she is wrong.
@georgetakei What pisses me off the most about all this is, that she apparently has a (of course estranged, because who would want to associate with such a phobic parent) transgender child, and still can't distinguish between transgender people and transvestites. Does she melt down at the sight of clowns or mimes as well?