This is addressed directly next to the animation in question. I'm surprised you didn't find out. The Sun's orbit changes with season. The animation focuses on Spring, roughly speaking.
Right, I get that, yet at no point during the spring on any point on earth is it the case that the sun literally does not set, at least not for more than exactly one day (Midnight Sun)
But by the model I'm seeing there, the sun would drift closer in during the summer months and farther out during the winter, yet that would leave weeks or even months in which parts of the world were in total darkness or total sunlight. Like, when the sun is at it's tightest circle (and I don't fully understand what makes the sun or moon move at all in these models, but more on that later) then the central pole would have 24 hour light for weeks and weeks and weeks as it gradually drifted back out, then the pole would be in total darkness for weeks and weeks and weeks.
Like, we literally know that just doesn't happen. It's something people can witness and confirm or deny year-round, and all deny it happening. Are we to assume they're all brought in on the conspiracy? How do the conspirators know exactly which people have witnessed the truth?
I feel like for all the conjecture in this movement, there seem to be few if any first-hand witnesses to the undeniable phenomena that some would have seen as a result of a flat earth.