Continuity mistake: During the big battle of the toy soldiers versus the elves, one soldier is approaching a screaming Abbie as his arms alternate between hanging straight down at his sides to bent at a 30-degree angle as the shots change.
Continuity mistake: After Santa marries Carol and kisses her, he puts his right hand on Charlie's arm. In the next shot, Santa's arm is down.
Continuity mistake: When Toy Santa sits at the desk, objects on the desk change around between shots. Most noticeably, the reading glasses (which he picks up for a moment and sets them down) are at an angle, then turned so the lenses face the camera.
Other mistake: Charlie spray-paints graffiti on the wall of the gymnasium to protest Principal Newman's refusal to decorate the school for Christmas. We see "Newman" in large letters, an equal sign and a decorated Christmas tree with a big red circle and slash across it. The letters have sharp, smooth edges and the tree and ornaments are highly detailed. It is obvious the graffiti was painted with brushes, not spray paint.
Answer: The actress dancing to "Everybody Loves Christmas" is Elizabeth Mitchell, who plays Mrs. Claus/Principal Newman.
wizard_of_gore ★