A polite/honorific way to refer to someone's face.
お顔を洗ってから寝てくださいね。
Please wash your face before going to bed.
初めてお会いできて、お顔を拝見できて光栄です。
It's an honor to meet you and to see your face for the first time.
その写真に写っているお顔は誰のものか覚えていない。
I don't remember whose face is in that photograph.