Red is concerned about the machine he saw in the factory. He doesn’t know what it does, but he knows there is something about it it that is bad. That angled conveyor belt is important, see. They still don’t know what the cubes are, but they know that they aren’t supposed to be grey. This machine will come back much later on, so much later that I haven’t even gotten close to bringing it back yet at the point I’m writing this, but it will come back and be important.