To understand what going on in the video, you have to know a little bit about Jedi Training Academy attraction that is located at Disneyland. According to their official website:
"This live-action show features several kids selected from the audience to don the famous brown robes and train with a Star Wars Jedi Master. Watch young Jedi trainees recite the sacred Jedi Oath, draw their light sabers and learn ancient battle techniques from a true Jedi Master."
So, what this kid did instead? She pledged her alliance to Lord Vader himself and pretty much trolled the freaking establishment. Astonishing trollin is astonishing.