Princess Diana’s brother Charles Spencer has revealed what he really thought of Kristen Stewart’s portrayal of his late sister in the 2021 film Spencer.And while Spencer did not have much praise for the film itself, he was genuinely impressed by Stewart’s performance, saying she managed to capture something he recognised in Diana.Speaking during a recent live conversation with journalist Tina Brown, Spencer recalled watching Spencer on a plane. He admitted that Stewart “doesn’t really look like Diana”, but what she managed to capture went much deeper than physical resemblance.“My goodness, she caught the spirit,” Spencer said, praising Stewart’s performance as “incredible”.He then made his opinion about the film itself clear, adding, “The film’s terrible.”Spencer went on to explain that what fascinated him was how effectively Stewart had understood Diana as a person. He said he was “really intrigued” by how good she was at capturing his sister.The comments offer a particularly interesting perspective because Spencer was one of the people who knew Diana before she became the global icon portrayed on screen. His reaction also draws a line between the film’s fictionalised story and Stewart’s work as an actor.Spencer, directed by Pablo Larraín and written by Steven Knight, is not presented as a traditional biopic. Set over a few days during the royal family’s Christmas gathering at Sandringham in 1991, the film imagines Diana’s emotional state as her marriage to then-Prince Charles was falling apart.Stewart’s performance became one of the film’s biggest talking points. She adopted Diana’s voice, mannerisms and body language, while also portraying a more intimate and psychologically intense version of the princess.For Stewart, the role was never simply about looking like Diana.In a 2021 interview with The Guardian, she explained that she had developed a deep emotional connection with the character during filming. “I believe in a lingering energy,” she said, adding, “I took her in.”She also described playing Diana as a physically demanding process, saying that understanding the princess’s distinctive way of speaking and behaving was almost like a “full-body exercise”.That emotional connection appeared to stay with Stewart long after filming ended.In February 2026, the actor spoke about Diana again in an interview with The Telegraph, saying she still felt “haunted” by the late princess. Stewart explained that she could not drive around London or Paris without thinking about Diana and the love that had surrounded her. “I can cry about her at any moment,” she said.Her emotional response to the finished film had also been evident years earlier.Speaking to CBS News in 2022, Stewart said she could not stop crying when she first watched Spencer. She described the film as being their “view” of Diana and “our love for her”, before adding that she felt the loss of Diana “so intently, so often”.Stewart had previously spoken about moments on the Spencer set when the boundary between herself and the character seemed to blur. In a 2021 interview with The Guardian, she said there were times when she did not believe in ghosts but also did not completely disbelieve in them, describing what she felt as a lingering energy connected to Diana.She had also said that there were moments during filming when her “body and mind would forget she was dead”, describing the experience as though Diana was somehow still present.That makes Spencer’s latest comments all the more striking.For someone who personally knew Diana, his assessment was not that Stewart looked exactly like her. In fact, he openly said the opposite. What impressed him was the actress’s ability to get beneath the appearance and capture what he described as Diana’s “spirit”.And that may be one of the most interesting compliments Stewart could receive for the role.Spencer’s comments also underline the difference between appreciating an actor’s performance and approving of the story being told. He may have dismissed Spencer as a film, but when it came to Stewart’s interpretation of his sister, his reaction was remarkably positive.For Stewart, meanwhile, Diana appears to remain a character she has never completely left behind. Years after the film’s release, she continues to speak about the princess with an unusual emotional intensity.And perhaps that is what makes her performance in Spencer continue to be discussed: it was not simply an attempt to recreate Diana’s appearance. Stewart spent months studying her voice, movement and mannerisms, but she also tried to understand the woman behind the public image.Charles Spencer’s verdict suggests that, at least in that respect, she succeeded.