Maybe someone replies. Maybe they don't. It's a low effort way of saying "Hey, I find this thing is worth 10 seconds of your time." My friend sent me a snap of her niece throwing a temper tantrum. It was funny. I chuckled. It disappeared. We got lunch weeks later, and I asked if her niece ever calmed down. She laughed, we moved on. She got to share a funny moment in her life with me (and presumably other people) because she thought I might be interested.
If she posted on facebook? You'd have people asking what was wrong, giving advice on how to calm a child, commenting about child abuse, and writing essays about the ethics of posting children to social media. Whatever.
If she posted on facebook? You'd have people asking what was wrong, giving advice on how to calm a child, commenting about child abuse, and writing essays about the ethics of posting children to social media. Whatever.