That thing is an electrical hazard and is just the parts stripped from an existing digital clock and put into another case. He should have designed it to be solely powered by the 9-volt battery connector (in the photo) to be safe but I’m sure that’s there to hold the time in case the mains power goes out—not the kid’s design. Obama should tell him that he didn’t build that, because he didn’t.
You are correct. The nine volt snap on terminal is clearly visible in the picture. Most DIY projects of such simplicity would be run on 9v or other battery power.