This is a square mug shaped like a set of traditional Chinese jade tiles lashed together with two tiles on each side and one tile at bottom. Tiles were used to make screens, lanterns and other decorations like this at the Mai-Kai (and other tiki temples). Released at the 2018 Hukilau.
This Chinese Tile mug was sold as part of a set of three from Tiki Diablo during the 2018 Hukilau along with a Blue Marquesan Mug and an Orange Tiki Mug.