Being glued to a phone makes it more visible and potentially harder to escape, but I wonder if it really changes much.
Girls have always treated high school as a popularity contest far more than boys. If anything, I suspect systematising it might even help, as it would replace "I am afraid that I am not really cool enough" with "I can see that I'm not and I have a plan to fix it". The latter might seem scary, but is it worse than silent angst and worrying? At least this girl is taking charge of her own popularity and learning how to shape her appearance from her peers, which in the absence of a mother might be the next best way to learn. I guess her dad isn't going to teach her much about female beauty techniques.
When I was a teenager I spent nearly all my free time on the computer, and when we got it, on the internet. It was only the fact that it tied up the phone line (and endless amounts of homework) that stopped me using it all the time. And of course my mother worried. She had very little visibility into what I was doing, it seemed to consume infinite amounts of time, and it was nothing like what kids in her day did. Plus back then there was a lot of fearmongering in the press about the (then new) internet.
You know what? I turned out fine. Nowadays she looks back on that period and realises she worried herself for nothing, heck she says she's actually embarrassed to tell other parents what her children are getting up to because it sounds like boasting.
The reason I spent so much time on the computer was simply that I lived in a very wet and rainy place far from parks, so playing outside wasn't really feasible, most of my friends lived too far away to just drop in on, and - the biggest reason - no matter how fondly adults today may remember them, traditional childs play activities were boring. There's only so much time you can spend on football even if you're sports mad.
In contrast the world of the computer had an almost limitless list of things to do, and many of them were very constructive.