I was in an MBTI mood, today, and I watched a few of your vids. You have some observations that I haven't run across in more clinical analyses. I thank you for more input to digest. I'm an INTJ (definitely 100% biochemical introvert), and I can explain the internal emotional feedback loop. I'm actually seriously struggling with it, right now. It's probably the worst part of being an INTJ (social disconnect would be the worst if I cared about it more). Also, I'd never thought about looking friendlier than other types, but you're right that it's just the outward shell. I probably don't look as judgmental because I have to consciously send a signal to my face to make the muscles contract to form an expression. That's probably the same mechanism at work that creeps you out when we 'disregard' you after you give an INTJ a new idea to play with. I usually appreciate new information and ideas, but I don't naturally react by giving someone a 'cookie'. So, for both my positive and negative reactions to other people, I need to be given a reason (or care about them enough) to think to offer evidence of my internal state. For better or worse, I do treat others as I wish to be treated. I don't usually care what non-close friends think of me, so I refrain from confronting others with what I think of them. Though, INTJs usually do need to incorporate some "general social niceness" into our social pacification routines or we're going to be perceived as arrogant robots.
"What other people think of me is none of my business."
P.S. If you're still curious about the horrible emotional feedback loop, I'd be happy to type up my experience with it.