https://forum.square-enix.com/ffxiv/...=1#post2776051

"While the creation of art can carry a different connotation than real money in terms of something to exchange for gil, your skills and the results of their application (in this case, art) are considered something of real world value. When considering it under this view, the exchange of art for in game currency would be considered a violation of the rules and may result in account actions."