It's so naturalistic

OP's first mistake was thinking they could find a picture of typical female bullying. Boy bullies may use their physical force, but most girl bullies use psychological force. They use words to tear into you, they manipulate people with lies about you, they create drama that drives friendships apart and socially isolates their target. There are no physical bruises to show for it, all the planning takes place inside their heads, and the closest thing to "evidence" is boiled down to "she said/she said." If she's got more friends to back up her lies (and she does, because she socially isolated you) she could easily turn the tables and accuse you of starting shit with her. And she will be believed. Because she's done it before - character assassination is her specialty, and she's targeted you enough that school admin prejudicially expects you to lie.

Anyway, you're probably not going to find a picture of that. Even if you do, you likely won't recognize it as "bullying" because it'll just look like girls talking.

Boy bullies may use their physical force, but most girl bullies use psychological force
There is a huge percentage of boy-bullying that is also psychological.
In fact, media is so terrible at portraying bullying that we still have made almost zero social progress against it, because the average bullying victim can't identify that the dudes in their group who say twisted shit to them or talk about them behind their back are actually bullies until they get older and the insecurity and trauma is set-in.
Physical bullying is common, but mental/emotional bullying among groups of teens is far more prevalent and goes completely unnoticed, and the digital/social-media age is making it even easier to hide entire worlds of abuse from parents.
- Yeah exactly. I've been on the receiving end on of (male) bullying quite a bit and also haven't always been nice to others myself in order to try and fit in. I can only remember one physical incident in all those years. That guy was the classic "movie" bully, just an asshole terrorizing everyone around him, so naturally I decided that something had to be done (it did not go well). Other than that it was all psychological. "Friends" that started saying mean things the moment they were around people they looked up to.
  Something that makes it a bit more difficult is also that bullying in these cases was often not black and white. The line between friendly teasing and psychological bullying was often quite thin. In hindsight I interpreted a lot of teasing jokes as bullying because I took everything literally and was very protective of my stuff. That doesn't excuse them because it was very clear that it hurt me, but it's interesting that some of those interactions now have become regular interactions between me and my friends that both sides clearly enjoy.
Anyway, you're probably not going to find a picture of that.
When I search "female bullying" images on ddg mostly show this. I thought the second image captured it pretty well.
The fifth result does too.
This one really captures the "just looks like talking" aspect you mention because it doesn't show the victim looking dramatically sad nor the bullies looking especially excited.
Damn, you just described exactly what some adult ex-friends of mine have done
Impressive
I've seen girls trying "boy bullying".
On boys.
Mostly ends quickly, and girl loses twice (got hit and dissapointed teachers).
Boys have "bouys will be boys" acting as a shield xD