How dark/bright are polar nights?
That's a timelaps video, most likely created from a sequence of photos. It's easy to choose sensitivity and ISO settings on normal cameras such that the night sky at the darkest night is over-exposed. The moon light looks like sunlight - as it simply is reflected sunlight.
E.g. see https://cloud.planetmaker.de/index.php/s/yJ7AXWG4dEC6csW - it's a an exposure of several seconds taken several hours after sunset in November in Kiruna, Sweden... the over-exposed part in the center are headlights of a car, the rest is illuminated by the nearly-full moon at that time.
As children of modern civilisation living in urban areas, we are simply not accustomed anymore to how bright even nights can be when you had sufficient time to adopt - and cameras can do that instantly. In arctic (or generally snowy) regions, the snow adds a lot to the overall brightness as it reflects the little available light at night extremely well.