POV displays are usually made from a pcb that have multiple Leds on it and that is connected to the shaft of a motor that rotates 360 degrees. The challenging part of this is to pass power and control signals to the rotating PCB. This is usually done via slip rings and carbon brushes. 

The neat part about this FlexLED project is that the PCB itself can generate the a flapping motion and create persistence of vision. It main disadvantage is its limiting angle which is currently set to around 120deg. But it eliminates the need of a motor which makes things simpler and cheaper. 

For example the total BOM of the first prototype is $2 which only consists from a flexible PCB and one LED (at 100pcs). This exclude the magnet and the other electronics needed to power the thing. But to generate this type of motion you would usually need a brushless motor which will add at least $10 to the total cost.