S.H.E-Ella singing "It's my Life"?

Ella from S.H.E sang the song "It's my Life" in a concert before, when and where did the concert take place? And what is that concert about?

I saw it from youtube:
http://www.youtube.com/watch?v=Dpqn25xV7Ac

Both Chinese and English answers are OK. I only use Eng because I am not good at typing Chinese.