I think there's an element of communication in this mix. As in, how people of a younger demographic communicate with each other - those they're attending the show with and those who aren't. I didn't find people to be recording lengthy sections of songs, more moments, brief videos. It wasn't just social posting either, it seemed more of an expanded, real time messaging approach. This was a stadium thing, seated, and the band weren't much, so this activity was far more interesting.
I personally find photographing the moment to be a chore and it limits my experience. But as a way of connecting with those in environments where it's hard to talk or you're separated, this is a different means of conversing. Something closer to meme culture I suppose.