What emotional signal might indicate someone is happy?

The choice featuring lips turned up and cheeks pushing up effectively indicates happiness due to the physical manifestation of this emotion. When a person is happy, their facial muscles typically react by lifting the corners of the mouth and causing the cheeks to become elevated. This is commonly recognized as a smile, which is universally associated with joy and positive feelings. Smiling also often leads to the eyes showing a slight crinkle at the corners, further emphasizing the expression of happiness. Such facial expressions are not only instinctive but also universally understood across different cultures as signals of a positive emotional state.