I just love the wind across the screen from left to right, the paper on the pavement moving with the wind and the circular cloud before the space shuttle lifts off.
You can edit your art at any point, including while it's in the approval queue. You don't need to resubmit just because you made a change.
Resubmitting your work resets the approval votes you already received, so it means your work will take longer to get approved. It can also confuse the people voting.
The approval system works like this:
You submit your art.
Users (Level 2+) vote on whether to accept it to the gallery.
Moderators look at your submission and decide whether to accept it. If it looks fine and has a lot of "Yes" votes, it gets accepted. If it has minor issues and a lot of "Yes" votes, it gets accepted. If it looks fine but has a lot of "No" votes, then moderators give it a closer look because they probably missed some problems with it, and perhaps let it stay in the queue longer. If it has issues and a lot of "No" votes, then it is not accepted to the gallery.
"Issues" that can slow down approval can be major things like a blurry image, but also minor things, usually things that can be stylistic choices as well as mistakes, such as noisy pixelling, like you have here.
Why do you keep resubmitting this before it gets a chance to be approved?
Thank you!