There's a couple of video clips of The Mushrooms performing at the festival on the official site. I say of The Mushrooms, this one is just of a girl on someone's shoulders with The Mushrooms playing in the background. This one is of the band though. It's only a minute long, but you can see Pupu doing his thing and hear people in the crowd singing along. It's basically more evidence that The Mushrooms are a top notch live act. According to this report, even the security guys were pogo-ing along.
Anyone who's read mine or Andy's blogs before no doubt knows all about The Mushrooms, so I won't go through the whole "I don't really like the genre, but I love this band" thing here. There's plenty about them on this site if you look for it. One link I will throw in though is to this video, which is the full version of 为什么你爱他, the track they're performing in the second video from Hangzhou linked above. Give 'em a play.
More photos of The Mushrooms at the West Lake Music Festival here.