They can, but with all the weird little artifacts in the image (and well, the creepy fucking expression on the dog…) I’m pretty sure this is AI.

Dogs “smiling” is typically a stress/fear response. Pitties kind of look like that a lot of the time, just because they have tight skin on their face/lips. But, this is more than that as far as I can tell here. You can see the wrinkling and tension at the corners of the mouth. This expression is also called a “fear grimace” or “submissive smile” and can also involve showing teeth, but not always.

Given the context, that it just destroyed a toy (something it may have been punished/scolded for in the past), I would bet it is nervous/scared. It could also just make weird faces - not all dogs are the same.