What is this thought bubble??

Hey guys! I'm wondering if anyone knows what this thought bubble means. Both my sim and their dog keep getting it above their head. I'm not sure if it's a CC thought bubble based off of some CC traits I have in the game or if it is regularly in the game. The dog doesn't have a CC trait enabled, only the male sim who has the trait of a scholar. My sims dog was a stray and I thought that might have something to do with it. But then I realized my sim was doing it as well. He was reading a book at the time. The dog on the other hand had this thought bubble while eating. So, I'm confused!

Anyways, I just thought I'd pop on here and ask because I'm curious. :blush: