First off - it looks awesome!
As for the requirements - Yup, just the submit entry button is a bit on the foggy side, so a mod would be better to answer (maybe ask in the general Art War QA), because it's newly implemented for this Art War.
N.B.! Do check the image sizes after you upload them for the final, cuz the site sometimes resizes (too) big files, so you'll have to either downscale it some more or, if impossible to downscale - compress it a bit.