I'd like to refer you to the forum rules.
If you post in the critique section it is but common courtesy to take other people's advice to your 'paper'.
In fact, you'll learn more by editing old works rather than just skipping to a new one. Also, try uploading your pictures at 100% resolution, where every pixel is displayed as just a single pixel, because the forum has built-in enlarging.
Apart from that, I'd reduce the dithering if I were you, it seems rather pointless at this scale and you could try simplifying the picture, or go the other way and increase the resolution and get in more juicy details if you want it to be this big.