Consisting of a round rail circling the drone, this rail pivoting on
an the drones vertical axis, a ribbon, light string or other visual
element would roll freely on this rail and be able to trail from
the unit in all directions.
If the unit went down, the ribbon due to induced drag would
itself to the top of the unit. If the unit flew sideways, it
would trace the horizontal path of the unit.
This would allow the unit to fly in all directions with the trailing
visual unit not getting tangled up.