Someone on another thread agrees with you:
>>224624
>>245073
"This simply highlights artifacts from anti-aliasing. The original image (Wikipedia's I believe) was just resized, and in the process of combining the data from two points into one, you get a color that is different from the adjacent pixels. Compression makes this worse, and messing with the color levels only highlights this. Notice that they appear at junctions where two colors meet.
Need proof? Look at what I did- take Wikipedia's flag (SVG) drop it into a raster file (PNG), and reduce the size to 310x163 (Q's version). Max out the curve with a dip near where the anti-aliasing would average the colors. It's not an exact match to the source but you can clearly see the same pattern."