I saw a girl with a seemingly fake smile at Walmart last night. Anyone else notice anything like this?

Last night, I was at Walmart and I saw a young girl with a smile that seemingly didn't quite look right. It almost appeared to be a drawing or painting of a smile on a girl. I'm not saying that it literally looked like a drawing or painting, but it seemed unnatural, and I can't explain it any better than that. It just looked like a smile that was slapped on her face. In addition to that, she didn't seem to be looking around at her surroundings, and she didn't seem to really be interacting with her family. To be clear, I didn't see her actually interact with them, but she just didn't seem very socially aware. It was weird. It almost seemed like she was following a program or something. I don't know. Just weird.