Earlier quoted context omitted.
I expect that someone with an assault weapon and what looks like a bullet proof vest is scary for quite a lot of people. And that's notable in the sense that is goes against the idea of "a peaceful event similar to a music festival" (paraphrasing).
But you see stuff like that at music festivals as well, in the form of police. So I'm asking why this is scary or notable but that is not.
Also I don’t know how are festivals in the US, but I’ve never seen armed cops at one, and would be really uncomfortable if there would be some.