Very interesting!
A very OT trail of thought that comes to mind.
There is a phenomenon that has a name that eludes me, "the ... gap" och perhaps "valley".
When something is rather different from a human, for example a monkey, you tend to see the similarities but if something is rather like a human, like a doll, you notice the differences. You are skillfully using this in making the correct differences which creates the "scary" impression.
Does anyone know the word I am looking for?