Pixelated Pop Stars: It’s Jessie J!
Answer: It's Jessie J as the evil lunch lady in her 'Who's Laughing Now' video! She also plays a self-absorbed teacher and a mangy janitor in the clip, which focuses around a mini Jessie getting bullied in grade school. But as the title indicates, this Brit gets the last laugh.
Watch the Jessie J 'Who's Laughing Now' Video