It took me a long time to figure out what it meant to smile when I had a picture taken.
I remember when I was very little, my mom telling me to smile. So, I'd have my mouth closed and pick up the corners of my lips. But I guess that didn't look happy enough, because my mother still complained.
I asked her, "What do you mean by 'smile' then?" She told me, "You show your teeth."
I was a little confused, but I did as I was told. I showed my teeth. Or, rather, I bared all my teeth, top and bottom, as far back as my mouth could stretch. I now have photos from my 6th birthday where I look like a wild creature trying to scare off a threat.
It took a couple years before I realized, "OHHHH, you're supposed to LOOK HAPPY in photos! I get it now!"
It was a really awkward revelation, because it suddenly seemed so common sense. Yet, I still didn't understand it until I was about 7 years old. Even after that, smiling in photos felt wrong. It seemed so fake. I thought that I should only smile if I was genuinely happy in that moment. I've gotten past that (of course, as my avatar shows.)
However, it makes me wonder. Since poor recognition of facial expressions is a common aspie trait, has anyone else had issues (or funny stories they want to share) related to smiling for photographs?