Girls are strange little creatures.
Don't ever try to understand why girls do things. You'll hurt yourself.
Not everyone do that. Generalization is never suit.
But mostly those who attend doing this is for gaining attention for something bad happened to them, depression, being suicidal, and in today's world ? Some people in particular teenagers use Social Media for drama and these kind of attention seeking and post their crying photos on there and gain comments, likes, PMs ect . . /
It's for the attention.
If I was younger I'd never do that...I'm an ugly crier people would have nightmares for weeks.
I don't know.