Looks like the AI can handle objects it "knows" (people, grass, sky etc.) okish, but is completely confounded by the Zeppelin - which is sad, as the Hindenburg is of course present in most of the shots. Maybe they should have trained it with some color(ized) photos of the Hindenburg (like this one: https://www.alamy.de/das-deutsche-zeppelin-luftschiff-die-hi...) first?