Also, I'd like to add that the dog looks excited when the owner begins to approach and then turns to the smile. But in a scared dog, the usual reaction would be to look away and cower or move away. The dog does none of this, and actually looks quite healthy. Those airplane ears are adorable. lol

My American Eskimo dog does this when I call her name. It's usually accompanied by excited whining and jumping, but she will stay still on occasion when she's been sleeping. She does look like she's scared when she does it lying down, but I know that she just doesn't want to move. The dog looked like he/she was very relaxed. And that sure looks like a smile to me!