Early photographs took a long time to make and people needed to stand and pose. So people are just tired, especially children, and appear to be sad in the photo. Here are a few examples of such photographs of the Victorian era.
There was a shortage of prison accommodation in the Victorian era, so long-term prisoners were transferred to provincial prisons, or to the dreaded hulks. The hulks were decommissioned warships anchored in the mud off Woolwich. They were dark, damp and verminous and few prisoners managed to escape. This is a cross-section of a hulk called the Defence, published in Henry Mayhew’s The Criminal Prisons of London, in 1862.