I think I'm pretty expressive, contrary to the stereotype that autistics don't show emotion. I smile and laugh a lot :)
Yes, I found out through another member here many years ago and she called them micro emotions. I had no idea I was making these expressions when out in public and I'd wonder why I was asked if I was okay,why don't I smile,etc. I find that I ask my son a lot if he's okay because sometimes he looks like he's upset.