Every once in a while you see a blur of glowing blue pixels darting from one shelf to another. After each dart, it briefly resolves itself into the form of a dark-haired girl in a hoodie and leggings with a basket under her arm, grabbing something off the shelf before dissolving into pixels again.

She may or may not be grabbing the best stuff just before you get to it. Vanellope is a brat like that.