One member, which received more than 100 merit in the art contest topic, wrote that he took the "base image" from another website, but at the same time his nickname is specified on the picture.
I suppose, this can make a confusion that this user painted most of the image.
I wouldn't know if this is "common" to do on artwork or not, but it is indeed confusing. Note that he
originally posted it without Credits, and edited his post 2 days later. I can't know for sure when during those 2 days the Credits were added.
It's still funny and fits the contest.