There's something deeply odd about Grazia's admission that it airbrushed Kate Middleton's waspy wedding waist for a cover story in May.

Deeply odd not because the princess clearly didn't need retouching – as an enchanted global television audience of two billion can attest – but because of the Frankenstein-style process that led, claim the magazine's staff, to the virtual liposuction. All manner of amputations and arm-cloning went on, to which one can only say... why?

We wanted, they said, "a great image of the duchess on her own, but all the photographs had the duke in too". Inconsiderate, Wills, very inconsiderate. "So we asked our reproduction house to remove him from the picture. This would have left the Duchess with only one arm, so they copied over her arm to complete it." Yes, that's definitely a lot less weird than just printing a picture of the married couple. I wonder how the future King of England feels about being cropped out of history when he is, if we're honest, the only reason Kate Middleton was on the cover in the first place. But that's by the by and he'll probably get over it.

Grazia claims that all the fiddling about, sticking Kate's lace-wrapped arms on back to front, or whatever it did, led to an "inadvertent" slimming of her waist. It "did not purposely make any alterations to the Duchess of Cambridge's image to make her appear slimmer, and we are sorry if this process gave that impression". Which is, I think, claptrap and all the more irritatingly mealy-mouthed when you consider that the magazine has run recent features headlined, "Should airbrushed images come with a health warning?" and "FINALLY! Debenhams ditches the airbrushing!"

Grazia is part of an industry, after all, which has been caught out stretching Kate Winslet's legs on a computerised rack in the name of a hot cover look. And which, month in, month out, digitally enhances already beautiful stars – whitening eyes, magicking away muffin-tops – to sell things and make the rest of the world feel bad so that they indulge in more retail therapy.

It's dishonest, isn't it? And while it's cynical when it comes to celebrities and fashion, it can be misleading and downright sinister when it comes to current affairs. This week, another queen, another cover, another double-take required. Michele Bachmann appeared on the front of Newsweek under the measured headline "The Queen of Rage". In an extraordinary image, the Republican presidential hopeful is blown up against a lurid teal background, bouffant mane nudging the skyline, mouth half open in a pearly rictus of surprise and fervour, eyes – oh those eyes! – maniacally staring and crinkling, as if possessed. She looks like a cross between Jack Nicholson in The Shining and Tony Blair in that New Labour, New Danger poster – but worse.

It's not clear if the art department had its wicked way with it but Newsweek has form. Two months ago it splashed with a creepy picture of how Princess Diana might have looked at 50, and before that it put Sarah Palin on the front in running shorts and bunches. "The out-of-context Newsweek approach is sexist... The media will do anything to draw attention – even if out of context," said Palin at the time, in a rare moment of clarity. It's been pointed out (on Slate.com) that no male Republican candidate has been treated to similar ridicule, so it's not only biased, it's sexist. Editor Tina Brown's response to complaints – "Michele Bachmann's intensity is galvanising voters in Iowa right now and Newsweek's cover captures that" – is as disingenuous as Grazia's. What both magazines understand is the power of images, and the power that comes with the ability to manipulate them into telling the story you want.

Take the rioters. Oh how we LOLed at those Photoshopped memes showing hoodies ransacking Barbie doll displays and looters looting lutes that popped up online before the smoke had even cleared. The real images they're based on are powerful stuff: for many, the summer of 2011 will forever be associated with the picture of a youth in a grey Adidas tracksuit, black gloves and face mask, striding through burning Hackney that appeared on the front of Tuesday's Independent. It didn't need any manipulating to tell its story. But as the infamous snapshot of the couple kissing amid the Vancouver ice hockey riot proved – was she injured? were they embracing? – even reportage photography can tell different stories from different angles. Cropped this way or that, waists slimmed down or eyes intensified, images can be treacherous. TV producers are not allowed to edit dishonestly. Radio phone-ins are policed more heavily than Tottenham High Road. So why are pictures – arguably the most powerful of all storytelling tools – so often exempt from the rules?

There are now several websites (see www.psdisasters.com) dedicated to Photoshop clangers where ghostly third hands have crept in, races have been changed and thighs shaved to Twiglets. I wonder if one day we'll look back at this flawed manipulation of reality in the pursuit of an ersatz perfect 2D narrative as a quaint technological hiccup – like the Sinclair C5 or MiniDiscs – but I fear not.

What were you doing while Brixton burned?

It's been a funny old week – in Edinburgh, covering the Fringe while my city burns. When my grandchildren ask me what I was doing during the Great London Riots of 2011, I will honestly be able to say that I was sitting in a painted crate in a disused church, watching a play about a witch on an iPad. It felt absurd spending five hours a day watching experimental theatre and comedy as feral packs rampaged down my Brixton street – but that's my job. So I've stood in queues checking Twitter and written reviews with News 24 in the background. Meanwhile, the Fringe has tried to react to events – comedians writing in looting jokes, producers plugging ballets which, if you squint, look a bit like a riot. But it's the shows that already addressed the issues of 21st-century living – performance poet Luke Wright's scintillating Cynical Ballads of Broken Britain, Team's bonkers history of American capitalism, Mission Drift – that have stood out. Perhaps 2011 will go down as the year the Fringe got serious.

Rappers, please stick to what you know

It's hard being a hip-hop fan. You wait years for your heroes to collaborate, then you patiently sit out the 10-month hype until you get to hear the results, and just when you're getting into that track that samples Otis Redding, Kanye West opens his mouth. This week Jay-Z and West finally released Watch the Throne, an occasion West marked at the Big Chill festival with an eight-minute tirade against the world and his poorly throat, climaxing with: "I walk down the street, and people look at me... like I'm Hitler. One day... people will understand everything I ever did." Not everything, Kanye. How is it that someone so sublimely in control of words on record instantly loses the flow when the backing track is switched off?