That is why it's better to make robots that don't look too close to humans so it doesn't look so weird.
https://en.wikipedia.org/wiki/Uncanny_valley
Yup, if the robot looks nothing like a real human or it resembles a human perfectly, then everything feels fine. But, in between is where it feels weird.
You'll probably experience more performance issues if you choose larger instances. On the other hand, it's harder to know how reliable and stable smaller instances are.