Said Björn Ståhl, quoted in "Why Burger King Is Proudly Advertising a Moldy, Disgusting Whopper/The chain's anti-preservatives pledge breaks just about every rule in advertising" (AdWeek)("The Moldy Whopper campaign, created through a partnership of three agencies features intriguingly high-resolution photography and video of a Whopper being consumed not by humans but rather by the voracious maw of time itself. In other words, we get to see a Whopper rotting").

Very beautiful, not that you want to eat it, but the point is that you eat it freshly made, and the mold that comes later proves its goodness on Day 1. And Burger King trusts its customers to understand the science and to enjoy the beauty of the artistically photographed food in its post-edible phase...
Snobs will say anyone sophisticated enough to appreciate this approach to advertising would never eat at Burger King anyway.
ADDED: Something you might not know about me is that in the year before I went to law school, I worked at J. Walter Thompson. The biggest client at the time was Burger King, and the big new campaign was "Burger King and I":