The spiraling of the phone at the end
The girls deserved it. This isn't about having "personality" or just "having fun"--the kids were being annoying brats, which is fine so long as they know it can come with consequences and reactions like this one. And they deserved it, so they should shut up and take it if they're going to dish it out.
And, yes, as a few others mentioned, the "Chinese" in the video title and the OP title is unnecessary. I know this may surprise some of you, but just because someone appears Asian does not mean they are Chinese.