“It’s a trend to be mindful in a way,” Olsen agrees. “I would never put salt in a smoothie.” Nevertheless, she won’t even contemplate sending it back.
“Actresses used to be crazy beautiful people living terrifying lives.” Referring to the celebrity-photograph-hacking scandal of last year, she adds that there would be nothing sensational if she ever fell victim to something similar. I do drink wine – I love food and wine, I can’t have one without the other.” Today she is drinking a spinach, kale, celery and hemp-seed smoothie – with an extra Vitamineral Green shot. “I’m not that person, I can never send anything back.” She adds that until recently she would never complain about anything and always took the blame if things went wrong. But then the other day I was at a photoshoot and something wasn’t working – I don’t know whether it was the clothes or the hair or the lighting – but instead of just saying, 'Why don’t we try something new?
In the past Olsen has said that she thinks she is a 50-50 combination of both of her sisters.
“I don’t know if that’s still accurate,” she tells me now.
“But I do think they are very different from each other.
In my mind they’re completely individualised.” Although she loved acting as a child – and even had a cameo, aged five, in her sisters’ film How the West Was Fun – she tried to suppress that as she got older.
“A lot of the characters have a snarky humour, but she’s not that person. She has telekinetic powers and can manipulate objects and minds.Petite and pretty, Olsen is instantly recognisable when she arrives, wearing gym clothes – an exercise top, leggings and black trainers – with her blond hair scraped back into a messy ponytail and a chic bag from The Row, one of her sisters’ fashion labels, over her shoulder.Down-to-earth and self-deprecating, she is seen as the most “normal” of the Olsen sisters, apparently unscathed by the media circus that has surrounded her family since Mary-Kate and Ashley made their acting debut, aged only nine months, on the American sitcom Full House.Contrary to popular perception, they were not pushy stage parents.In fact, they stumbled into the industry when a friend’s child’s agent mentioned they were looking for twins to share a role in a new sitcom.