I suppose we are watching different streams.
On my, Zhenya has a pokerface on, and only starts to smile when she sees the camera is doing a closeup on her.
Ok Zhenya isn't as happy as she would be if she won a gold obviously, but I think you're been unfair to her. She had a bad injury last year and has been working hard to overcome it.
For whatever reason she felt she had to move onto a new coach, that's her right. Was it the best decision for her career? Who knows? But she's the only one who can decide what to do with her own life.