I just finished watching the iTunes festival, not her best, I agree with some of you, her vocals were a not strong compared to her previews performances, I hope is just the nerves tbh, I don't want any Adele vocal chord type of problem.
Anyway, Without You and Video Games were my favorite performances, WY because of the emotion and vocals, and VG because I love seeing her interacting with the fans, she's so cute, I swear I'm going to meet her someday....