Guild Wars 2: Heart of Thorns’ upcoming guild halls will undoubtedly serve as a focal point for community interaction and shared efforts. Before they arrive in the game, however, ArenaNet wants to offer a way for players to put their personal stamp on these zones by creating emblems for the halls.
Therefore, the studio is running a guild emblem design contest from now through August 1st. Players are encouraged to whip up interesting artistic designs and submit them in the hopes of having their emblems chosen as the best. The five winning designs will not only be incorporated into the game as housing design options but be gifted along with various prizes as well.
You can read more about it on the official contest page.
Source: Guild Wars 2