I don't know? She looks very poised and reserve. It might be cultural
Many fans noticed that too, Vietnamese fans talked about it a lot during Olympic time and it made us even more sad, worried (and yes, more angry). It's one of the reason we are glad that she retired, because she won't have all the lonely time like that ever again.
Hmm from what I remember from the Sochi gala practice, Yuna wasn't super outgoing, but I definitely remember thinking she talks to more people than some of the others.
Some people noted she looks lost here because she "was late to practice": https://www.youtube.com/watch?v=pBXbmYHmKkM (Look at 2:20!!! SO CUTE! like a penguin! ^_^)
But she looks so cute! ^_^ And also, that expression totally makes sense after you have skated flawlessly on your second Olympics and got second place, as you were probably beginning to suspect before you even skated. Her expression looks a bit dazed.
More Yuna laughing at 1:10: https://www.youtube.com/watch?v=24nENP3Lqas
In a way I feel kinda sad for her and also feel bad on the other skaters not talking or approaching her. But I guess that's what I love about her. She's a gentle sweet soul. And I hope she stays that way.