Have to agree with twinny this just would cause alot of drama and basically even if it was added in the game.. I bet there will be tons of copyright or even edited pixel art that has been used in various games/anime.. Simply anyone can google search pixel art and even tho some artist who works on graal knows a few stuff here and there doesn't mean they would never miss 5% of the uploads which are copyright which has been done in the past with hats/heads...
The reason for the initiative is simple, staff sees your work throughout assignments every member can preview each other content while this assignment is due. Just to make it even more clear a few members in the past have pointed out stolen/copyright material and show a few members who have been fraud in the guild which helps out a little more than just depending on one or two staffs to know everything. I believe the person had uploaded one of the hats from zodiac but then again you guys wouldn't know cause the forums are private.