For some celebrities, revealing all is part of the product. For others, it looks like a deeply unpleasant chore.This past summer, Celine Dion manufactured a breathtaking cultural moment. It was at the opening ceremony of the Paris Olympics, just after a long, daffy and highly maximalist buildup to the lighting of the Olympic cauldron. Suddenly, there she was, standing on a terrace of the twinkling Eiffel Tower in a scintillant Dior gown. As she sang, a swell of both applause and what sounded like a collective moan of pleasure rose from the audience. Celine Dion was alive and singing. And if you didn’t cry, it could only be because you didn’t know.It was hard not to know. A few weeks before the Olympics came the release of “I Am: Celine Dion,” a well-publicized documentary that took viewers inside what had become of her life since she became largely housebound with stiff-person syndrome — an exceedingly rare disorder that, in Dion’s case, causes terrifying whole-body spasms so severe that they can break bones. Anyone who has watched “I Am” knows what these crises look like, because Dion allowed herself to be filmed during one of them, for 10 minutes, her body frozen in agonizing contortions. By that point, we were already familiar with Dion’s universe of deep illness; we’d seen her holed up in her Las Vegas compound, surrounded by doctors, unable to walk properly, unable to sing properly, often supine, her body distended, her skin raw. In terms of radical transparency, “I Am” is a milestone: a completely new standard for Bravely Baring All.Dion is far from the only celebrity to have invited the public to witness life with a serious illness. Lady Gaga’s 2017 documentary, “Gaga: Five Foot Two,” revealed the star’s daily struggle with fibromyalgia, and in last year’s “Still,” Michael J. Fox — a groundbreaking figure in celebrity-illness transparency — further tugged down the curtain on how severe his Parkinson’s disease has become. Selma Blair, who spent a portion of her career hiding symptoms, eventually revealed a diagnosis of M.S. and then began posting intensely personal bedside updates on social media. Last year an issue of British Vogue had her on the cover, in a skinny beige column of a dress, patent pumps and a cane, with a headline announcing her as “Dynamic, Daring & Disabled.”For fans, these narratives can create a kind of whiplashing feelings roller coaster. You see Lady Gaga diminished and sobbing because of unrelenting full-body pain — and then, soon enough, suspended from the top of a Houston stadium for a Super Bowl halftime performance. You witness Celine Dion in a heartbreaking, horrible fit and then belting out an Edith Piaf song from such great heights. The intention here, surely, is to show that such stars are only human, that their lives and bodies have the same potential for suffering as ours. But the insane highs and pitiable lows these stories offer us feel almost inhumanly extreme. And in watching them, I began wondering if the stars in them didn’t end up feeling caged by the seemingly necessary Hollywood framing in which inspiration and drama need to take precedence over nuance and open-endedness. Dion and Gaga have to adapt to illnesses for which there is no known cure. So what do they do now? The answer is synonymous with their job: perform.Middleton’s video just feels so weird.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe. More