How's this any different from mindlessly listening to generic pop music and reading teen magazines?
This is where all the stress comes from. Young girls are under enormous pressure to be attractive and gather tons of likes from their peers. The feedback loop has tightened so much that it reinforces the repetitive behaviour of posting and checking for likes. It's addictive!
But that's the problem. People get a "like" or equivalent on a photo or post and they conflate that with self-worth. They then see their friend (or worse, enemy) get more likes and either feel unworthy or a need to compete. I get the short-term self-esteem boost from a popular post, but the long-terms effects of chasing such positive affirmation are not healthy and will likely to lead to deeper issues later in life particularly once you enter the workforce.
Disclaimer: I went to school pre-social media so insert appropriate dinosaur reference.
What do you think about the evidence that more teenagers than ever are suffering from severe anxiety?(https://www.nytimes.com/2017/10/11/magazine/why-are-more-ame...)
Teens can understand magazines have a known aspect of theatrics, whereas the assumption is that instagram is reality and like a Pavlovian dog you must present your life in such a way to gather bonus points from other internet users.
It's a way of building reputation , such as how programmers use Github, but because of Instagrams's resizing and compression of photos it's only an interest-generator; the full experience is on Flickr or 500px or whatever. But apparently it's the most lucrative channel for picking-up paid work.
It's also somewhat easier for parents to monitor their kids' magazine consumption (if only because magazines cost money), while it's hard to do the same for IG.
Social media is practically a Skinner Box (https://en.wikipedia.org/wiki/Skinner_Box) with a very tight feedback loop. The randomness of the reward approaches an optimal conditioning schedule.
Listening to pop or reading a magazine doesn't have anywhere near that level of power.