Check out Christina Aguilera's heavily altered 'Voice' promo pic

Christina Aguilera is looking pretty good in the new advertisement for her NBC singing competition, "The Voice." Perhaps a little too good.

The photo is, to paraphrase many an Internet commenter, a bit too perfect (just check out this candid photo of Aguilera at a recent press event). Regarding the promo pic, a commenter over at TooFab.com writes, "Well duh of course she looks good. Photoshop fixes everything." Another posted: "Nice Spanx."

But it's not like Aguilera is the first celebrity to undergo a little digital alteration. Supermodels do it. Britney Spears did it, but then released both the pre- and post-airbrushed photos so folks could see the differences for themselves. Beyonce's skin tone underwent an odd transformation between two magazine covers.

And the airbrushing doesn't stop there. The cover of Adam Lambert's "For Your Entertainment" album is so clearly processed that it borders on the bizarre. In one case, an ad for Lancome featuring Julia Roberts was banned in the U.K. for too much photo manipulation. 

The thing is, though, the subject of the photo is in trouble either way. Take, for example, the case of Sarah Palin. Palin's photo on the cover of Newsweek was not digitally altered, and people were rather shocked to see that she looked like a regular person with flaws and wrinkles.

Digital alteration isn't always about celebs. One unfortunate example came from Target Australia. The male model in the shot appears to have three hands. One of our personal favorites came from a wedding where the father of the groom wasn't able to make it on the big day. The bride inserted her father-in-law into the wedding photos, with no attempt to be subtle.