Please make sure you read the rules on the submission page. Uncontrolled anti-aliasing, like the painted (smuged?) red here is not allowed in the PJ gallery.
By the way, the full size image is optional. When your preview image is the entire artwork, you don't have to upload a full image. Doing so just causes it to appear twice on the page, which looks silly.
I am really sorry for my mistakes... i will remove the red background and put something different