To smile gently; to form a soft, quiet smile.
彼女は子供を見て優しく微笑んだ。
She looked at the child and smiled gently.
冗談を言ったら、皆が思わず微笑んだ。
When I told the joke, everyone couldn't help but smile.
写真を撮るとき、自然に微笑むのは難しい。
It's difficult to smile naturally when taking a photo.