This looks like it's made in the Windows 7 version of MS Paint - it has same kind of antialias that windows 7 mspaint applies to the lines.
There is 727 colours in this and the outlines are really blurry aa though you may have accidently stretched this or something. Also I don't really read it as a giraffe
Automatic anti-aliasing. This isn't crisp enough to be accepted into the gallery...might I suggest you recreate the piece with more pixel-level detail?