You'll notice that this blackout is quite short - in fact, it's more like a brownout. How are the flashlights returning? The key is to understand that these flashlight-bearing proteins are not permanently bound to DNA. They are constantly coming on and off, too fast for the eye to see. In our case, the zapped proteins with dead flashlights are quickly being replaced by fresh proteins with functional flashlights. Using this method, we can measure the on/off rate of these proteins on DNA. This graph tracks the brightness of a zapped (blue) and an unzapped (olive) region over time; it takes about 30 seconds to fully replace all the proteins in the zapped region:
Your body may look stable, but experiments like this demonstrate that there is constant motion inside every cell, much faster than the eye can see. These experiments are also really fun because you get to fire a laser at a cell - it's kind of like playing a video game, only tinier and real.