From the facial expressions in old photographs, we can infer relationships. If two people are smiling and standing close together, they were probably friends or family. We can also learn about historical events. The look of worry or fear on people's faces in photos taken during a war or a natural disaster can tell us about the impact of those events. And sometimes, we can see the influence of fashion. A certain hairstyle or makeup can affect the overall expression, and this can tell us about the beauty standards of the time.