"I don't want my picture taken," the 21-year-old actress tells Entertainment Weekly magazine. "The only time I think it's OK is at a red-carpet event or a photo shoot.
"So every time I see paparazzi, I cover my face so they don't get a picture, and I'm just 'the mean person who doesn't smile.' "
Olsen, whose waiflike figure has made her a target of media scrutiny, avoids public displays of attention.
After a hiatus from acting, Olsen -- who rose to fame on TV's "Full House" in a shared role with twin sister Ashley -- will portray an alluring Christian girl on Showtime's "Weeds." Her 10-episode arc begins Sept. 17.
She also returns to the big screen in "The Wackness," co-starring Ben Kingsley. The film is slated for release next year.
"There's definitely been times in my life when I just turned to people and said, 'I'm done, this is too much for me, this is too overwhelming,' " Olsen says.
She's in a healthy frame of mind these days.
"Mentally, physically, I feel pretty on top of my game right now," Olsen says. "Talk to me next week, I don't know. Today, I feel good."