system
Given the following post, respond as if you're commenting on Reddit:
human
[Toy Story 4] How can Bo Peep move as well as she does.

So it’s been kind of the law that a toy can only move using its own articulation, with some slight leeway allowing for Toys with no articulation to hobble. 

Bo Peep is a porcelain figure. How is it she have fully fluid human movement when only loose toys have been able to accomplish that?

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Edit: okay so I think I’ve been “Mandela Effect”ing how some of the movements worked in previous films. Looking back it seems that the Army men can move freely apart from their feet are a plastic stand, and Hamm can waddle about dispute being a piggy bank.

I think what is happening is Toys can move the way they are imagined too by the child. So in absence toy articulation limits their movement because that’s his the child sees them move in their head. Where as with a more rigid toy a child can sometimes picture more movement in their head.
gpt
Bo Peep, being unowned by a child for a length of time, has become her own "imaginator" if you will.  Instead of a child imagining her moving, she's imagining herself - and thus her actual movement is more athletic and fluid.  

(trying to come up with a "canon" line of reasoning)