At one time a lot of the more common collectors pose Argies (Cotton Candy, Minty, Snuzzle, ect.) started turning up with different symbols. It's been thought that someone used original symbol stencils to put new symbols on "cheaper" ponies, making them sell for higher prices on ebay. The most common symbol to be found on these is Fluttershy's butterflies, but this Sweet Stuff falls into that category, too.
Some people view them as legit variations, other people view them as not "original" the same as a rehaired pony... beauty (and value) is in the eye of the beholder.