1A facial expression — the way emotion shows on someone's face, often used to read how a person is feeling.
合格発表を見た瞬間、彼女の表情がぱっと明るくなった。
The moment she saw the results, her expression suddenly brightened.
面接官の表情からは合否がまったく読み取れなかった。
I couldn't read the interviewer's expression at all to tell whether I'd passed.
赤ちゃんは色々な表情を見せて、見ているだけで飽きない。
Babies show all kinds of expressions — it's fun just to watch them.
彼は怒っているはずなのに、表情には出さなかった。
He must have been angry, but he didn't show it in his expression.
2A broader sense of 'expression' or 'look' — the way something comes across not just on the face but in voice, tone, or manner, including artistic or performative nuance.
ピアノの演奏には彼女らしい柔らかな表情があった。
Her piano performance had a soft expressiveness that was distinctly hers.
ナレーターの声の表情が物語に深みを与えている。
The expressiveness of the narrator's voice adds depth to the story.