I picked up this AUish 1903
IHC not long ago and on the second feather from the bottom of the headdress is a copper bubble of some sort. At first it looked like dirt but under a 15x magnifier it looks like part of the surrounding metal. Sorry if the pics are poor quality:


Is this some sort of mint error or a die variety? My main worry is that it could be a fake, but of course that's unlikely given the abundance of this date. Thanks