Apparently, there's this culture where arrows don't indicate "forward", but "backward". When you see an arrow, you are supposed to run in the opposite direction of its point.
This is because, one day, in a year when the stores of dried dung hadn't been abundant enough to provide insulation for the winter provisions, the culture stumbled upon a method of momentarily slowing quark rotation to the point that they invented a rudimentary hyperdrive system. Unsure of what to do with it, and with their elders insisting on the creation of focus groups and a sub-committee to oversee the environmental impact of any further experiments, the bumbling savages' top scientists inverted the propulsion tracks on the platform destined to carry sacrificed virgins in the following day's tree-worshipping ceremony, and thus all the controls on the platform (which were marked with arrows) ended up pointing the opposite way than the platform would actually travel.
The driver (hired on seasonal contract from an entrepreneurial neighbouring tribe), was so bewildered by the controls that he piloted the platform into the lake, where it miraculously floated to the very center and then began glowing with a benevolent pale light, and records show that all the tribe members agreed that over the Sky-snake's next shedding cycle, there was no war nor disease.
This fortuitous event occasioned a great respect for the back ends of stylized arrows, and from that day the barbarians have always understood an arrow to mean "move backward away from my point".
That is why we need to introduce the "arrow-direction-signification" parameter, to take into account whether our generated arrows should point towards or away from the location to which we want to direct our users.