The laser-cut claw is interesting looking and the brains are an Arduino. You can see the action in the video below and there are plenty of older videos on the project page.
Without the PCB, the machine was a mess of wires. With the PCB, a single ribbon cable connects the Arduino to the board, and the board has a layout of screw terminals. This results in a much cleaner layout than before.
You might think you wouldn’t see many homemade claw machines. However, that’s not true. We’ve seen plenty, some of them even using commercial claws. Naturally, some of them also connect to the Internet.