The photos on the main page are down-sampled, so never show the true quality of the photos. Which is why it's good to upload a High Resolution photo.
Go to;
My Stuff
my contest entries
find this entry and click on ;
edit entry
Upload the image again
remember to tick;
Also save full resolution image.
Your image doesn't need to be enormous, anything between 2.5mg and 3.5mg is plenty big enough.
Good luck

very moody

The HIgh Res looks even better.

beautiful shot

Nice angle, might have given it a higher vote, if there had been a High Res.

I am amazed by the signs of the tide, nice picture