The American Sniper star appears alongside fellow A-listers Domhnall Gleeson, Lily James and Dominic West in The Tale of Thomas Burberry, a holiday project for the British fashion brand directed by Amy director Asif Kapadia.

So far the ad, which is fashioned like a mini-movie, has received over six million views on YouTube, and Sienna has confirmed there has been talk among her friends in Hollywood about potentially expanding the campaign into a drama for the big screen.

"A lot of people keep asking that - not just people on the internet, but, like, people I know," she tells "Obviously if it becomes a film, I would love to be a part of it. It really does seem like everybody wants to see the full movie."

Sienna admits she was blown away by the quality of the ad's screenplay, noting, "It felt really dramatic on-set! The script had a lot of character development. It was easy to fall into the story."

However, there is one major thing she regrets - not taking home the gorgeous clothes she wore onscreen for the short film.

When asked if she kept some of the costumes she wore for the project, the star responded, "No, which is really annoying, isn't it? I have such a good relationship with the Burberry team. I should probably be a bit better about asking them... You know, the dress I wore in the party scene is so beautiful that I might beg to borrow it."