I think it's at least partly the grin - I assume they were aiming for friendly/welcoming, but to me it looks like it is about to start nodding to itself before

I think it's at least partly the grin - I assume they were aiming for friendly/welcoming, but to me it looks like it is about to start nodding to itself before doing something unpleasant to someone. Toned back slightly, I'd probably have not noticed it.