Why is THIS "low-quality"? I mean, yeah, it's got a retarded file size, but other than that, the quality of the art itself is excellent. This is why I've always disagreed with the quality filters--they simply do not work.
What Mark says. If votes show that the users think this picture has better quality than what the tag says, it will be changed.
Remember that the first high/medium/low quality value is more of a first impression rather than a final one. Votes will help measure what users feel and we'll adapt to it.
All users are welcome to help with their votes, adding tags and source links. :)