The world’s longest and deepest railway tunnel (the Gotthard Base Tunnel), going straight through the Alps, officially opened recently in Switzerland and was celebrated with a lavish pageant featuring, among many other things, some costumes and processions very reminiscent of traditional mumming. I’m guessing the German director drew inspiration from Alpine mumming customs, although perhaps taking some liberties in their presentation.
Of course, most people aren’t aware of these customs, leading to the internet going crazy with rumors of the opening ceremony being a “bizarre occult ritual” or having something to do with (of course) the Illuminati. The goat-man set off some Satanic panic as well. I suppose they are at least partially right, in that these customs do have something to do with dark spirits – but they are generally meant to ward them off, not invite them in!