Basically it is an LED-based eye sweep circuit that emulates the original bulbs. You can program the sweep speed and "decay rate" of the LEDs to match different bulbs. This gives a longer or shorter comet tail effect seen in bulbs. You can also program the "on time" of the LEDs to also emulate a bulb since they do not come on instantaneously.
Here is a video:
https://www.youtube.com/watch?v=R-H6IqYqUgw
I may offer kits of these if there is interest. I figured people here could appreciate the amount of work to make this look correct.

Thanks for looking
-Jim