From an ELLE Quebec interview:

The type of woman that attracts Viggo

How is this friendship disrupted by the insertion of a woman of intrigue, played by Renée Zellwegger?
"I can’t exactly tell you how! But let’s say I really like Renée’s role. She’s depicting a complex woman, perhaps manipulative, but very touching in the way she admits her fear of being alone. In that way she shows herself to be both vulnerable and honest."

Is this the kind of woman that attracts you?

“I like women who are honest, with others and with themselves. And if I’m lucky, with me too! “(laughs)

You’ve met such women?
(long silence) “Honest women are rare, you know...”

Why do you say that?
(He evades the question and turns it back to me: ) “Why do you think?”

Err....my opinion? Let’s say that it happens that some women are more attached to their image than to their true nature.
“Indeed, but it’s not just women that are trapped by their image and who dare not express what they really are. The same goes for men. Such men are sometimes caught up in their idea of masculinity and the roles they believe they have to play in society, or in their private life. And of course, one has to be ready to take risks to be in a couple. In fact I think that having the courage to be oneself is the most difficult thing in the world. The most essential and also the most magnificent."

more of the translated interview