The annoying musical trend of 2003: bubblegum-pop-stars who try to prove how deep they are by singing about how it's really OK not to be good-looking or popular. Different is in, kids!
The talent-pool of people who can sing and dance well enough to be a pop-star is pretty much infinitely deep, especially with modern studio technology. The top of the pool is skimmed by the record-companies based on the current exhaustive market-research (or who is sleeping with the boss), and then marketed to death on commercial radio.
So someone selected from this process singing about how great it is to be different is more than a little ironic.
Now, if Miss Aguilera were singing about how it's really quite acceptable to be a skanky ho, it'd be a different story.