Steven Universe has a Nintendo Gamecube in their Universe. But instead of being called a GameCube... it is simple... "Dolphin". pic.twitter.com/REeAt7TBCA— TRAFON (@RiseFallNick) January 23, 2020
The GameCube might not be getting new games nowadays, but the controller still lives on. Its been a method of input for the Wii, Wii U, and now Switch, and plenty of fans use one to throw down in Smash. It seems the staff of Steven Universe have some Cube fans on their staff, as they've just included a tribute to the system in a recent episode.
As you can see in the images above, the controller has Dolphin written on it itstead of GameCube. For those who are too young to know, the GameCube's working name was the Dolphin before it released to the public. Whoever snuck in this reference knows their Nintendo history!