I was with my friend at a bar in Osaka, and we'd had a few. The waiter came over and set down a circular change tray. I being a little intoxicated assumed he wanted me to use a coaster, so I picked up my glass and set it on it. He was not amused by this and shot me a VERY stern look - and then it clicked. We left soon after, quite embarrassed.
We'd been in Japan for almost a week at this point, so we'd seen it all over the place and knew full well about the practice. The tray was just usually a rectangle as is the one in the article.