'The Image of You': 'Pretty Little Liars' star Sasha Pieterse plays twins in mysterious thriller movie

Pretty Little Liars fans will remember that twins were all over the mysteries revealed on that TV show. Now Sasha Pieterse, who famously played Alison DiLaurentis, has stepped into her own twin-related thriller with the movie The Image of You, based on the book by Adele Parks (now in select theatre and available to buy on digital).

"When I read scripts like this in the past ... I'm like, 'I know where this is going, I can read right through it," Pieterse told Yahoo. "So when I read this script and I didn't expect [the twist], and I was just shocked, it really intrigued me."

"I was like, OK well this is different, this is unique, and how cool I get to play two people. What a fun challenge for an actor. ... I just kind of got obsessed with it and I just couldn't stop thinking about it. I knew what I wanted to do with it, I knew how certain scenes would play out, I was just so excited about it."

Sasha Pieterse prepared to play twins by walking around her house

In The Image of You we meet Anna and Zoe (both played by Pieterse). They're identical twin sisters who have been particularly inseparable for their entire lives, something their mother, played by Mira Sorvino, is quick to point out. When Anna starts dating and ultimately falls in love with Nick (Parker Young), Zoe is suspicious of this relationship. But as the story progresses, deadly truths are revealed.

For Pieterse, she was tasked with developing two different personalities for Zoe and Anna. One of the interesting things that helped Pieterse develop these two characters was actually walking around her house.

"I was like, OK Anna will walk like this, Zoe will walk like this, and establishing that to the degree that it's natural, where I can just bounce back and forth between two characters," Pieterse said. "It's a challenge that I loved."

"It's just kind of developing their backstory, things that aren't necessarily on the page, favourite colour, things that they hated, just random things that really make up a person and help step into their shoes. ... Tone of voice is one thing, Anna's is more soft and her voice is a little higher, and Zoe's is much more seductive, and raspy and lower. ... And then different hair and makeup makes a huge difference, you really feel like you've stepped into somebody else."

Republic Pictures, a Paramount Pictures label

Watch The Image of You

The Image of You is available to buy on digital

$18 at Apple TV

Pieterse's costar, Parker Young, called her "incredible" for being able to navigate between these two characters.

"Just as a human being, she's just an incredible person and so much fun to work with, and really took this seriously, and wanted to try and find two different personas, Anna and Zoe," Young said.

"My scenes were with Anna first, at least the first chunk of our scenes are together. ... I remember when she first showed up as Zoe, I felt like I was cheating on Anna. I felt like I was meeting some new person, some new actress. So she did such an incredible job of creating two different people."

Parker Young was 'scared' of this aspect of his character

For the character Nick, it's easy to be incredibly suspicious of his motives pursuing Anna at the beginning of the movie. Young highlighted that he loves playing a character that "isn't incredibly likable" on the page.

"To find this guy's humanity and hopefully get the audience to fall in love with this person, despite his flaws, despite the things on the page that maybe seem less than desirable," Young said. "I like to believe humans, for the most part, are good people, and so I try to find the good in the characters that I play."

"My hope is that people could almost want to root for Nick and start to understand where he's coming from. I think that's a very interesting dynamic, to have a guy that you don't think you want to like, but you do, and you can understand why he does things that he does. ... Nick gets put through the meat grinder. ... It's part of what what scared me about this project, was where he has to ultimately go emotionally, something that I haven't had to do as an actor, or thank God as a human being in my real life."

'After having a baby, this is the most revealing thing that I've done'

Particularly for Zoe, at the beginning of The Image of You Pieterse taps into that sort of intimidating mean girl essence (not unlike the demeanour of Alison DiLaurentis in Pretty Little Liars). Pieterse worked to really understand the motivation for a character like this.

"Everybody is the way that they are because of what's happened to them in the past, and you're a product of your environment," Pieterse said. "It's kind of just finding what makes people tick."

"So with Zoe, she had a really troubled past, and it's such a mixture and concoction of bad circumstances from young childhood, and where she is now. It's difficult. So the way that she handles certain situations and the way that she takes power over people, and things, is due to what happened to her and how she grew up. So that is her coping mechanism, 'Well before somebody hurts me, I'm going to control and hurt them.' And I think it's so toxic, but that is her reason behind it."

The actor added that stepping into a character that's sultry, flirty and powerful "is really fun," but Pieterse also revealed that she felt quite empowered to be stepping into her most revealing role since having her child in 2020.

"After having a baby, this is the most revealing thing that I've done, and to own that and to own my new body, and to own the way that I feel as a woman now is really important and empowering," Pieterse said. "So I left with such a happy, content, feeling and experience, because I feel like, no matter if nobody saw this movie, I know how I felt when I shot it, and it's special in that way."