Kate Middleton has always been thin, but when the Duchess of Cambridge appeared on the cover of British fashion magazine Grazia on May 9, the 29-year-old looked noticeably more slender than usual.

The reason? Grazia doctored the cover image of Middleton in her custom-designed Alexander McQueen wedding gown.

The magazine claimed it wanted a solo shot of the newlywed, but editors couldn't find a suitable picture without Prince William on Middleton's arm. By removing him from the picture, Middleton's right arm had to be altered to match her left to make it look as if she were striking a pose.

Britain's Press Complaints Commission determined that by "mirroring one of the Duchess' arms,"  the "inadvertent result of the change was the slimming of her waist."

A rep for Grazia told Today that the waist-slimming effect was unintentional.

"We 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," the rep said.