If you look around you now-a-days many teenagers are on their phones, taking selfies and also making videos. This crosses over in to real life when going to conventions, meet-ups and sometimes in just day to day life. Being on social media usually sets the bar for appearance and personality very high and unrealistic, as photoshop and facetune/meitu are widely used by young teens and adults to make their photos look more attractive. Personality wise we see people with with overblown egos from fame, or the opposite, very closed off and depressed people due to the pressure to be beautiful as the filters make others seem online.
Also makeup and wigs/extensions and glamorous skincare routines may cause teens of households with lower income to feel left out and sad as their more well off friends can afford these things. At school sometimes cliques will form of people who have a large following on social media, which will exclude people who don't have a large following themselves. On top of this people will push their opinions from social media in others faces in real life, such as political views or who their favorite sports teams are without properly knowing how to back up their claims because they read all their information online from an article without supporting claims or evidence.