In that video is a striking little girl that was perfect for Elizabeth's character design!
It's important that Elizabeth is kind of over-the-top sweet at the beginning. So when she changes in the 2nd + 3rd volumes it's super dramatic. She isn't the same person at all in the last story arc.
I don't want to spoil it, but her evolution is my favorite part of the 3rd volume.
I've always felt Elizabeth's character was so overlooked in the many adaptions of Frankenstein.
And hopefully it's something that sets my version apart.