I think I'd look that way too in the circumstances
I know exactly why this look is on Kele on Bloc Party's face.
If you go on You Tube and look up their performance of "This Modern Love" from Lollapalooza 2008, you can hear him scream "come on" when barely any of the audience is clapping.
The next day, disgusted with the fact that the front of the crowd was people camping out for Rage Against The Machine, the lead singer of Brand New threw his guitar at the drummer.
Kele didn't do the same thing after getting disgusted with the Radiohead fans, but I couldn't have blamed him if he did.