From Amsterdam: A History of the World's Most Liberal City by Russell Shorto:
If you go online and search "Anne Frank video" you will find a twenty-second snippet of black-and-white footage. It was shot in Amsterdam on June 22, 1941, right around the time Bob de Jong wrote his poem to Frieda Brommet and just before the Nazi presence in the city became a horror. A couple on Merwedeplein got married on this day, and a friend captured the bride and groom leaving their apartment. Three things stand out in this simultaneously remarkable and humdrum bit of film. First and most obviously, as the camera pans upward for an instant you see Anne Frank, just turned twelve, pop her head out the window of her apartment to watch the couple step out into the daylight in their finery. What is striking is not only that we have here the only existing film footage of her but that this quick flash actually gives a sense of who she was. Nearly everyone who knew her remembered Anne Frank as fidgety and quick-witted, the kind of girl who could be a handful for her parents. Watch the film and you see her give one sharp turn of her head to say something to someone inside, presumably her mother or father. It's a sassy motion; it brims with attitude. It fits precisely what we know of her.
The second thing the little film shows is the new section of Amsterdam, whose construction Floor Wibaut oversaw. It's all fresh and clean looking and, most of all, modern. This is not the city of Rembrandt. It's not even the city that Vincent van Gough wandered during his sojourn in the 1870s. It's recognizably a place that any of us today would feel at home in: you can almost hear the flush toilets flushing, and you know that, come evening, electric lamps will be snapped on.
The third thing that stands out is how normal life looks At the end of the clip the camera pans down the street. We see people strolling, people on bicycles; two cars turn a corner. It's a calm sunny day and a couple are heading off to their wedding while others take casual note.
Over the previous year or so, as Nazi Germany made its first moves to swallow chunks of Europe, the Dutch had remained astoundingly at ease. They believed that history would repeat itself: as they had twenty-six years before, they declared themselves neutral, and most Dutch people thought that, as before, the combatants would respect the declaration. Indeed, Hitler vowed in a speech to the Reichstag that he would honor the Dutch stance. Then the next day he ordered the invasion of the country saying, with some accuracy, "Nobody will question that after we have conquered.”