"Move in the mirror faster than the speed of light"
The speed of light is ~300000m/s. Lets say your mirror is 10cm long your movement would have to be as fast as 3000000m/s at least? This shit only works in theory you know. Although when they first tried to measure the speed of light they were like in the mountains somewhere and took a kilometer distance apart with mirrors and then let the sun mirror from it. So I suppose it should be a very long ass distance, huge mirrors and nothing to stop the beams in the middle. Those conditions and other ones that are required are pretty much impossible to create.
The artist of the picture is trolling you, that's all.