I was not there but they look to me like the design of one of the old sets starter deck playmats. Like both of them combined. It was Dragon I think. But maybe I am just crasy.
It is from EX : Dragon. I saw them in a tournament during the season 2004-2005. And I was surprised to see them at our National this year ; I think Asmodée had a lot of them in stock ; I have 2 of them at home I think.