Is Vox championing themselves as the purveyor of historic photographic B.S. or something? First their “color film is racist” garbage and now this. Perhaps in the early days of daguerreotype photography the “it took a long time” (even though it was no more than ten seconds) thing could hold water, but the truth is that people didn’t smile in vintage photos because dental practice during that time was terrible and no one wanted to be known for their crummy chompers. Yellow teeth turned up black on orthochromatic film, which was blue-sensitive. Not until the 1920s did panchromatic (all-color sensitive) film turn up. That coupled with good dental hygiene are the reasons the smile began to become ubiquitous in photos.