could you describe and explain about this sentence:?

Question

"It's the red van, spinning a trail of fluff-balls down the hill."
1- Do you know what is a fluff-ball?
2- I want to know what does "down the hill' mean: does it mean that the van brings the fluff-balls down from the hill? or it means that the van brings them along the hill?
Thank you for your help.

Answer 1

I believe that the phrase "fluff balls" indicates that the tires are causing a trail of dirt/debris behind the van and that the author is trying to make it sound better than saying "a trail of dust".

The van is driving down the hill, with a trail of dust behind it (caused by the tires).

Hope that helps!