There are plenty of reasons to be frustrated with celebrity feminism. In the past couple of years young, pretty, mostly white celebrities have started rushing to assure the world of their sparkling feminist credentials.  The most cringeworthy moment surely came last September, when Chanel’s Karl Lagerfeld – a man whose grasp of feminism had previously been restricted to the insight that ‘no one wants to see curvy women’ – staged a mock feminist protest on a Paris catwalk. Nascent grassroots feminism suddenly became just another way of selling clothes.

But despite all this, we shouldn’t absolutely condemn celebrity feminism. Feminism is at its root very different from the other causes that celebrities jump on. When Leonardo Di Caprio talks about climate change for the UN, few seem to notice or care. But when Emma Watson stood up and made that He For She speech last year, social media exploded.

The reaction to Emma Watson’s speech strikes at the heart of why celebrity feminism matters. First, Watson talked about her own experiences of sexism, recalling that the media started sexualising her at the age of just 14. Of course, the experiences of one of the wealthiest women in the world will inevitably be very different from most women’s. But there’s a reason that feminism starts from the principle that the personal is political.

Throughout history women’s issues have been belittled because they are concerned not with the public sphere but the personal, the private. Watson’s ‘personal’ will be very far from mine, and farther again from the ‘personal’ of the 15.5 million girls who she says will marry as children in the next 16 years. But that does not make her experiences of sexism and inequality any less true. And in speaking out about those personal experiences she links them to a wider system of oppression that affects everyone.

What is more important, though, is that celebrities’ personal experiences are not just their own experiences. In a Hollywood where only 15% of screenwriters and 9% of directors are women, women on camera are all too often simply sexist caricatures, as the Bechdel test demonstrates. Off-camera, the press scrutinises female celebrities remorselessly. And that has consequences that go beyond those women as individuals.

When Miley Cyrus is forced to deny that she is pregnant because she dared to appear in public with body fat, or when the press sexualises even young girls in the public eye, it tells all women that they will be forced into narrow categories and judged on them. Paradoxically, the women who seem most powerful are actually used to oppress and belittle other women.

So when Beyoncé chose to open her fantastically successful last album with the song ‘Pretty Hurts’, or when Cyrus called herself a feminist, or when Watson made that speech, it changed what it meant to be a female celebrity. Without rejecting all the tropes the entertainment industry uses to define women, female artists have shifted the meaning of those tropes. Recently Taylor Swift – another convert to feminism – did just that in her ‘Blank Space’ video: Swift takes sexist scrutiny of her personal life and turns it into a parody that forces us to laugh at the stereotypes we foist on women in the public eye.

Increasingly, instead of accepting the two-dimensional images the media makes of them, female celebrities are taking control of the interplay of those images. And when that comes together with a declaration of feminism, that act of subversion becomes explicitly political. From this perspective, Lagerfeld’s mock protest starts to looks like a doomed attempt to take control of a movement quickly escaping the boundaries of patriarchal control.

All this isn’t to say we should sit back and applaud celebrity feminism. It’s still just as true that celebrities are the winners in a system that overwhelmingly favours young women who conform to Western beauty standards. Correspondingly, we should expect that they will have an interest in maintaining a status quo that disproportionately values what young, rich and privileged women have to say. But neither should we reject celebrity feminism altogether. In claiming feminism, celebrities strip back the images and illusions that the media uses to oppress women, and show us that they are not just caricatures but real, complex individuals; individuals, in fact, like all women are.