2D Boy's members used to write for The Sims
They have unsubtly hinted that they are former EA employees, and World of Goo's fake loading screens and lighthearted jabs at pop culture are a staple of The Sims. The Sign Painter also painted the 2D Boy logo at the beginning of the game.
It does kind of look like a sign... The player works for the Corporation
Why else would it be the player's goal to collect the goo balls? In addition, the message requesting access to the Information Superhighway's recycle bin says it needs to be approved by a representative of the Corporation. The message goes to the World of Goo Corporation public terminal, which has to be accessed by the player.