Small improvements for testing feedback

[timrozum]

1. Reduce video flicker when track is shown or getting switched back on. There was both a blue (from the view that is shown when camera is off) and black flash so the flicker was particularly bad. I got rid of the black flash. Might be able to improve the blue flash later.
2. Display Bob (You) instead of just You. This is more consistent with the web app.
3. A couple copy changes.