The only known footage of Anne Frank, watching from a window as a wedding procession begins in the summer of 1941. I found it via an article on The Smart Set, which sums it up far more articulately than I am capable of. Much more can be found at the Anne Frank House Museum Amsterdam.
What's always been the defining nature of the tragedy of the Franks, for me, was the ordinary nature of the family: these weren't war heroes or spies or members of the Resistance fighting the brave struggle. They were simple people just trying to keep their heads down and survive an onslaught that was beyond their understanding-- in short, they were me if the same thing happened to my world. Watching this very ordinary footage, with its very ordinary teenager doing what any young girl would do with such an event happening under her window, amplifies that.
Knowing what happens such a short time after this footage was recorded makes it tragic beyond words.