When Lizzie's dad saws through the chain on the door, it is obvious that the cover is still on the saw.
When Matt is shown eating a popsicle really fastly, he finishes and shows his nice clean popsicle stick, and his mouth is relatively clean. Yet a few shots later his mouth is covered in purple mess.
During the opening shot, as Lizzie and Miranda are walking along in the lunch queue as they are talking, Miranda looks directly at the camera and smiles as if she had expected the shot to be over. As soon as she realises it isn't, she turns away.
When Miranda puts on some music, and Gordo walks over beside her saying how "raccoons wouldn't want to stay for her singing", as he stops, you can see his and Miranda's tape markers.