I may be bad at reading facial expressions and may be assuming the best scenario (...) but that person seems a bit sad to me. Maybe to feel connected to others?
That's a contrived expression, and not one of genuine sadness; he's pulling a face, not expressing an emotion. You can see on his GitHub profile he's got a similar facial expression, although a little less pronounced. [0] It's kinda like his duck face!
I think this has just been created for giggles, not for any particular reason. Admittedly, it piqued my curiosity!