As far as I know this guy is on it's way to Dunkirk in 1940 so not a very happy moment in history. This photo comes from a tv documentary about that period.
You have to refresh you page. When you visit the same website often the computer doesn't take all info from the internet but some items like photos from the computers memory to be faster.
You should have an option to refresh the page you are looking at, often it's an arrow in a round shape.