I'm actually surprised Jessie J got this gig because her album 'Sweet Talker' didn't sell very well, and she stopped promoting it after 'Bang Bang.'
She was most likely pitching for 'Flashlight' off the 'Pitch Perfect 2' soundtrack and threw in 'Bang Bang' and 'Burnin' Up' for good measure. Her pert little ass looked so good in those tight sparkly pants and she delivered a dynamic vocal. Sexy performance with loadsa charisma!