“That's a great look on you!”
You meet your friend for lunch. She got her hair cut a lot shorter than usual. You say this because you like how it looks.
That's a great look on you!
"A look" is a certain style of hair, makeup, and clothes. You can say what kind of look a person has:
She has a classic, traditional look.
I'm going for, like, a really edgy look.
That's a nice look!
There are other meanings of "a look" as well:
- The emotions you're showing on your face:
She gave me an angry look.
- Quickly checking on something:
A: The coffee maker seems to be broken or something.
B: OK, I'll give it a look.
When you think a person's hair cut, makeup, or clothes match that person well, and make that person look good, you can say that it "looks good on" them:
Oh wow, that dress looks so good on you!
This might seem natural for talking about clothes because you put them on, but you can also talk about hair this way:
I think that's a nice hair style on you.
Or just this:
That's a nice look on you.