Meaning: This sentence means that the friends experience a positive emotion when they share laughter.
Choice of Words: The word "are" is used to describe the state of being of the friends. The word "happy" is an adjective that describes the emotional state of the friends. The word "when" is used to indicate that the friends are happy at the time they are sharing laughter.
The friends feel joyful as they share laughter.
Meaning: This sentence means that the friends experience a strong positive emotion when they share laughter.
Choice of Words: The word "feel" is used to describe the emotional state of the friends. The word "joyful" is an adjective that describes the positive emotional state of the friends. The word "as" is used to indicate that the friends feel joyful at the same time they are sharing laughter.
The friends are filled with mirth as they share laughter.
Meaning: This sentence means that the friends experience a great deal of happiness when they share laughter.
Choice of Words: The word "filled" is used to describe the emotional state of the friends. The word "mirth" is a noun that describes a state of great happiness. The word "as" is used to indicate that the friends are filled with mirth at the same time they are sharing laughter.