The wiki for pixie cut says: "The pixie cut is a type of women’s hairstyle that typically features short hair cut at around the chin's length or less, with descending volume from the top to bottom and little to no styling." Accordingly, it's tagged on a lot of pictures of characters with chin-length-ish hair, like post #6300566 and post #6298168.
However, when I think of a pixie cut, I think of something much shorter and choppier, like post #6183816 (which is also tagged with pixie cut, ftr). A quick google shows that's the definition most people seem to use (e.g. all the pictures in this article, which even at their longest are visibly shorter than the two posts linked above).
I don't think these should be tagged as the same hairstyle, as people looking for one probably aren't looking for the other. Can we split the longer examples off into their own tag, and if so, what should it be called? chin-length hair? Just short hair?