User blog comment:Darkcloud1111/Good Idea, Bad Idea~Extracurricular/@comment-4403232-20140830002703/@comment-3146930-20140830003538

But she is a world class fighter, so I'm assuming that somewhere down the line people have figured it out. I mean if she was forced to use it against other people during fights, I'm sure word would spread kind of fast. Not to mention that Sun and Neptune enter the room and at this point, Pyrrha may have never met them and as far as she know, they are just two random people coming to watch the fight. A fighter of her level wouldn't not know they were there. Plus they are in a room full of large glass windows that anyone could be looking in. I'm sure Beacon also has a detailed list of a student's skills, including their Semblance but that is just speculation.

It is Emerald that mentions her Semblance being Polarity after all, but if no one knew what her Semblance is then how do they know it isn't something like telekinesis, which is the ability to move anything.