Rooney Mara on the cover of November's Vogue.

How hard did Rooney Mara have to work for “ The Girl with the Dragon Tattoo?” She got her nipple pierced, hair chopped, eyebrows dyed and posed topless, to say nothing about actually acting in the film. Also, she barely ate.

A profile of Mara and “Dragon Tattoo” director David Fincher in the November issue of Vogue describes an awkward dinner with the pair in Sweden, where the film was shot:

“When a waiter appears to take our order, we are all looking at our menus, but I see out of the corner of my eye Fincher nudging Mara. He says with quiet seriousness, ‘You can eat.’ I look up to see her reaction. Mara rolls her eyes, and Fincher laughs. ‘You can have lettuce and a grape. A raisin if you must.’ She orders a piece of fish and barely touches it.”

Anticipation for “Dragon Tattoo” has reached epic heights not just because of the popularity of Stieg Larssons’ novels but also because the original Swedish film series won much acclaim. The bar is high.

“One of the things that make our version that much more heartbreaking,” Mara told Vogue, “is that even though I am playing a 24-year-old, I look much younger. I look like a child.” Asked if she had to get unhealthily skinny for the role, she replied, “Umm . . . not really.” Fincher added, “It hasn’t been too hard for her.”

Mara took further steps to get fully into character as the antisocial, hostile Lisbeth Salander:

“She mentions a time Fincher said, ‘Go out and get really, really drunk and come in the next morning so we can take pictures of you.’ He wanted to show Sony that she could look strung out. ‘And I did it!’ says Mara. ‘Threw up all night!’”

The trials didn’t stop when the camera started rolling. Mara reflected on how she felt shooting the film’s many violent rape scenes.

“I don’t know how to describe it,” she said. “I think, physically, it was hardest. I got really beat up. But I gave myself a few days and then I was fine.”

Now, on the brink of becoming Hollywood’s Next Big Thing, the homely brunette from “ The Social Network” is wondering how all of this will play out.

“I’ve been trying to really live in the moment because I will never get this part of it back,” she told Vogue. “As soon as the movie comes out, everyone will turn it into what they believe it is, so I’ve really been trying to appreciate every minute of now. Because I know what’s coming.”