It would've been a lot better if Diaz and Keener switched parts

Keener's character oozed power, sexuality, flippancy, confidence. I think that's what made her so irresistible to everyone. Not that she was a supermodel. She's like that uber cool, unattainable person you just want to like you. And Keener is attractive too. (Meaning...I don't think being beautiful was the point of the character, yet, she needs to be at least good looking to pull it off)

Spike Jonze's movies have actors looking as unatractive as possible. I'm guessing it's because he wants the audience to see them as regular people instead of movie stars. No matter who had been cast as LOTTE she would've looked that way (think Amy Adams in HER). MAXINE was meant to be an atractive but not super hot woman, so Cameron would've been wrong for the part. Not to mention Cameron was trying to show the world that she can act. If she had played the chick the main character falls in love with inmediately, she would've been typcasted.