I told my wife she was drawing her eyebrows too high.

This one-liner delivers its chuckle through clever wordplay, specifically a pun. The humor hinges entirely on the double meaning of the word "surprised." When the joke's narrator tells his wife her eyebrows are drawn too high, her reaction of "looking surprised" plays on two interpretations. First, she might genuinely be taken aback or astonished by his comment. Second, and this is where the punchline lands, the physical act of raising one's eyebrows high is a universally recognized facial expression for surprise, creating a visual gag with words.

Eyebrows, it turns out, are surprisingly expressive. Throughout history and across cultures, the position and shape of our eyebrows have been crucial non-verbal cues, conveying everything from confusion and anger to, yes, surprise. Many people also enhance or reshape their eyebrows as part of their daily beauty routine, aiming to frame their faces or achieve a particular look. The joke cleverly taps into both this common beauty practice and our shared understanding of facial expressions, making the punchline a delightful visual image painted purely with words.