He found her eyes fixed on him with an angry expression.

他发现她的眼睛带着愤怒的表情注视着他。

youdao

A slight narrowing of the eyes is an instinctual, universal expression of anger across various species in the animal kingdom (think about the angry expressions of tigers, dogs, etc.).

轻微地眯眼是出自本性的一种表达愤怒的方式，对于动物世界里各种各样的动物都是通用的(想一想老虎，狗等动物生气的表情就知道了)。

youdao

I could tell (that) he was angry from his expression.

从他的表情我看得出他生气了。

《牛津词典》