A bold guess:
Looks like the main line goes once around the orange thing.
Then, by pulling the lighter line, it makes the black winder spin, which makes the orange winder spin and hence makes the whole structure climb the main line.
I would imagine that due to weight (i.e. gravity) if you let go the lighter line the whole contraption moves down which makes the orange winder spin in the opposite direction, which makes the black winder spin likewise and makes the thin line be re-spun around the black winder and be neatly put away.
If this is how it works it is quite clever... (not me, the invention I mean)