What kind of smile is "skin smiles but meat doesn't smile"?

People's eyes don't lie. In fact, "skin smiles but meat doesn't smile" means "your eyes betray your heart, and your heart is not happy".

The easiest way to recognize her is to cover the lower part of her face and imagine what her mouth looks like and what radian is more harmonious and appropriate. If her eyes are not full of joy, but her mouth is wide open, her radian is upward, and her mouth is upturned, it is not a heartfelt smile.

Of course, there are many kinds of smiles, such as contempt in the eyes and smile at the corners of the mouth. Eyes without a trace of temperature, a trace of joy, a trace of restraint, people away from the smile. A happy smile is a smile everywhere. This is a harmonious and comfortable smile!