Face pro quo
You do something stupid on social media just so your friend will do the same. It's like you're both trying to win a stupid game. No one wants to be the last one to look dumb.
'That movie was awesome!' (while you watched it on your phone in the bathroom)
'You look like a superhero!' (because you're wearing a shirt from your mom's closet)
'That trip was the best ever!' (while your trip was just a 10-minute walk)