It would seem that even the most bona fide of stars can't just turn up to a US Vogue cover shoot, pout for a while in fairytale frocks and then let the wizards in post-production do the rest.
Indeed, the thought of 11 million pairs of eyes drinking in your cover is enough to make the most powerful of personalities drop a dress size (Oprah Winfrey famously lost 20lbs for her star turn at the suggestion of editor-in-chief Anna Wintour) or deny themselves many of life's little pleasures in preparation.
In fact, quite the opposite appears to be true as the Firework singer admitted that she did "a lot" of her own prepping to look her best.
Perry said: "I kind of went on a cleanse… I did a lot of stuff like vitamins and supplements and changed my coffee to green tea and I didn't drink any alcohol for three months so I was really in the zone, I just wanted to be glowing for that cover."
Not wanting to rely upon bronzer and good lighting conveys Perry's dedication to the cause - and by sharing that nugget of information on national television, we're sure the message will get through to Ms Wintour herself - who in turn might reward Perry with a second cover...