The 31-year-old actress, who won a Best Supporting Actress Oscar Award back in March, discusses her sudden fame and her style aesthetic in the magazine's July 14 issue.
"It just feels like the entertainment industry exploded into my life," she told the mag. "People who seemed so distant all of a sudden were right in front of me and recognizing me—before I recognized them!"
Nyong'o said she first noticed the change last January, when she arrived at the airport after the SAG Awards.
"For a split second I looked behind me to see who they were flashing at -- and it was me!" said. "That was, I think, the beginning of the end of my anonymity."
Nyong'o said she designed many of her own clothes growing up in Kenya and recalled her prom dress, "a velvet miniskirt with a matching little top and an iridescent silver translucent fabric that flowed to the ground."
Nowadays, Nyong'o said her red carpet looks can take up to six hours to choose.
"Especially for the bigger awards, the dress let me know it was going to be worn," she said of her selection process. "It's quite scary when you fall in love with a dress, because it's nothing to do with your brain. It's like a gut reaction."
Nyong'o's next project a much-hyped role in Star Wars: Episode VII, which should hit theaters late next year.