Daguerreotypes are an early form of photographs.
Paris street scenes, as they appear in those daguerreotypes, have an unreal quality about them. There are no people. It took many minutes for these early cameras to take a picture, and during that time people would have come and gone, leaving not even a trace in the final print. What remained was only the solid motionless part of the city. Perhaps they would have found a modern photograph of a street scene unreal, with people caught n the middle of taking a step, or a child jumping rope miraculously suspended in the air, never to touch the ground again.