Sadly, I can't read due to paywall, so thank you for the other link.
I think this is very worrying, and it seems 20 years ago, before we had facebook and smartphones, this was far less of an issue. Social media is well known to be having a serious detrimental effect on people, esp young minds, not developed enough to cope fully.
Part the issue seems to be the Algorithms that dictate what people see, time and time again we see kids being sent messages about harm, due to what they are searching for, even if those serches are innocant, kids are curious, so may look up self harm to find out more info generally after hearing about it in the news, they should find credible info, but the opposite seems to be the case.
Molly Russell is one high profile victim, there is also a report on self harm images from Plos One
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0238603
Which, granted is from 2020, but still important.
Girls worry more about how the look, it is important to them they are under a lot of pressure to conform to ther fake looks presented by influencers or celebrities or boys perhaps expect them to have big breasts, due to the material they see, giving them a skewed idea of what people look like. it is like trying to walk across a tredmill, you won't reach perfection, or the price you pay for doing so is high.
Problem is that pressure is on them from an earlier age. Interesting the CEO of samsung, would not let kids under 12 have smart phones. But everyone is forced to have a smart phone to just interact or buy items in shops for example.
I can't see big tech changing their ways as they care more about profits.