Whats wrong? (bike chain) or is there even something wrong?

Hi, I just went to get my chain replaced, and when I started cycling, I realised that the chain was making strong noises whenever I was cycling a bit harder. Then, when I checked the tension, it looked like in the video.
Is it normal? I also want to say that I know that this guy didn’t even move the wheel, since it’s in the same place, and that’s giving me a bad sign.