What does it mean for a person to praise your healthy smile?

This shows that you are praising your cheerful and energetic personality, and it also shows that you are not good in other aspects-if you are not beautiful enough, if you praise yourself for being beautiful, you will know yourself and think that he is insincerely praising you. This is a compliment to foster strengths and avoid weaknesses-otherwise, the other party will not speak at all.