Meaning: He shut his eyes and formed a smile with his mouth.
Choice of Words: Closed means shut. Eyes are the organs of sight. Smiled means to form a smile with the mouth.
Alternative Expressions
He shut his peepers and grinned.
Meaning: This sentence means the same as the first sentence, but it uses different words to make it more interesting.
Choice of Words: The word "shut" is another way of saying "closed." "Peepers" is a fun word for eyes. "Grinned" is a synonym for "smiled," but it means to smile really big.
He squeezed his eyelids together and formed a pleased expression on his face.
Meaning: This sentence means the same as the first two sentences, but it uses more detailed language.
Choice of Words: The phrase "squeezed his eyelids together" means to close your eyes by bringing your eyelids together. "Formed a pleased expression on his face" is a fancy way of saying "smiled."