This is a well directed film from a director who appears to know what he needs from his actors, and camera operators. He especially manages to portray the lead character Lisa, played by the great Joan Fontaine very well. And Fontaine gives this renowned director what he wants. She plays both the vulnerable and later the hardened Lisa in her mature role adeptly. The very handsome Louis Jourdan, and the Vienna setting are turned into props by the director to exaggerate Lisa's vulnerability.
It is within Lisa's vulnerability that the audience can see how the concept of romantic love has been used to make women emotionally needy, which can then be taken advantage of by the likes of Jourdan's character Stefan. In the real world, romantic love becomes a commodity for transacting a deal which secures relationships. Therefore, women play up to the idea of romantic love, rather than succumb to it, and use it as a meal ticket for their security in a man's world. This is illustrated in the film by Lisa, who later marries a man for financial security, as well as respectability, as opposed to love.
After several viewings of this film, I have to say it's one of the best around!