Oh god no! Who wants to be seen with a woman that looks like Liam Gallagher?

yuk.

She was an extraordinary looking woman so mono-brow or not she was a stunner. Depends on the face underneath. Personally I think it look a bit odd, I have a male friend who has one and he's cute.

i think the reason it worked for kahlo was because she embraced something about herself that other people considered ugly and ran with it. let's not forget though, that self-deprecation is a major theme of her work and she often shows herself mortally wounded -- a kind of suicide through art. she wasn't exactly proud of her unibrow; she was just obsessed with it.
in real life, it's not a sexy look on a girl or a guy.

In some cultures it is considered 'sexy' on a woman, in others (like here in North America) its considered an extreme turn off.
Frida Kahlo was also from a different time, different place.

Some cultures are less picky about body hair on women.

And some people think strength of personality is sexier than any mere physical attributes.