Translation:They are beautiful.
Here they use beatiful.
Also, it might not be a woman but a feminine noun. For example, if you are talking about a man's eyes. (Bad example, I know, my mind just went blank and I can't think of anything else)
We have "nice" as a hint, since sometimes you use "nice" when referring to nice-looking objects. But you should think of יפה mainly as "beautiful", "pretty". If you say a person is יפה, it doesn't mean they're nice, only that they're nice to look at! He is nice: הוא נחמד.
So, this can be "nice", as long as הן refers to some feminine-gender objects.