Burger King is breaking the mold in its new advertising campaign. The burger chain is portraying its Whopper covered in mold in print and TV ads running in Europe and the U.S. The message: Burger King is removing artificial preservatives from its signature burger. The company, already known for irreverent ad campaigns, turned it up a notch, including a time-lapse of a decaying burger on Twitter. That imagery goes beyond the print ads that show a 28-day-old burger _ a week beyond. Early reaction to the campaign Wednesday was a mix of applause for the shift away from preservatives, to disgust.