If you didn't recognize Emmy Rossum in Angelyne, we wouldn't blame you.

The actress, 35, looks like an entirely different person in the new Peacock series, which follows the real-life story of pop culture icon Angelyne, who graced billboards across Los Angeles in the '80s. When it came to transforming into the billboard queen, Rossum told E! News that it took major makeup magic and some well-places prosthetic cleavage.

"It's all prosthetics," she said about recreating Angelyne's famous bust, "and I think that's what's so incredible about our incredible hair and makeup team."

In fact, the actress wore 3-pounds of fake boobs (a breastplate was glued to her torso) that left her with blisters, she previously told The Hollywood Reporter. She also relied on two different pairs of contact lenses, heavy eye makeup, and a platinum wig. Oh and she bleached her naturally dark eyebrows.

Her physical transformation was certainly a team effort, as Rossum told E! News, "Everyone worked hand-in-hand with my movement coaches and vocal coaches to kind of help create the icon that is Angelyne."