@lain Because she's essentially not, she's a background detail. She has the same level of animation detail as the bag they put Maggie in: just look at how her neck swivel goes from a whole body motion showing concern for her baby to a single neck rotation. It's lower quality than an animated GIF from 2003.
The whole intro is basically just an excuse to go "hey remember this character?" or "hah callback to something 20 years ago" and everything is cut down to make room for all the references