Did you know you can create drawings and share them via social media? It’s true! Just visit the mailbox in Inkopolis Square. Your drawings may be viewable by other players, so don’t go posting personal info or inappropriate content, knuckleheads! These drawings may be displayed as signs or graffiti in Inkopolis Square.
— Squid Research Lab
Source: Splatoon’s Tumblr.
…Wanna play? Buy a Switch.
And if you’ve already got yours, click on Splatoon 2 for everything you need to know about the game. 😀