Wow, there are some beautiful and interesting images being posted here!
It's been difficult to get the images at the poles to look right. Because the lighting angle is always so low they have huge shadows. We try to remove image cut outs that are mostly shadow, but some completely blank images seem to have got through. Just submit the image without marking anything for now. We may add a 'bad image' button in future, or improve the removal of bad images to minimise their appearance.