It's not so much about confidence and the outward appearance of it, it's about a deep sense of FEELING. There are places in the body that actually generate that feeling of love and security and when we experience trauma or adopt negative self images we close ourselves off to those parts of the body on a subconscious level. A lot of confidence building techniques are just intellectual exercises, they don't really work with the body when it comes to releasing pent up emotions.
Her childhood has caused her to disassociate from the love within, which is why this exchange with such an inconsiderate a$$hole has come about.
No 6 year old should be worried about their weight or who they compare to but unfortunately in the world we live in we put a lot of ideas in childrens heads that end up influencing their whole lives from the background noise of their psyche.
Hopefully she takes this experience and looks deeper into it and realizes he was only saying what she was thinking...he played the external role for her own inner critic.
naw, she's just one of those broads whose parents let her get raised by the tv and other kids that don't know any better, spoiling her, giving her lip gloss and make up at 4 years old and etc instead of actually parenting her. i'ma also guess that she's one of those hipsters that is living off of her parents money too where she doesn't have a sense of responsibility. it's always somebody elses fault. this is what happens when parents don't stay active in their kids lives, act like they are their kids best friend and then they grow up to do dumb shyt thinking it's normal and BLAMING other people.