I think the thing under the white circle is a spark gap, but I'm not positive. My question is how does this LED blink without any capacitors?
There are two possibilities:
- The LED is really an integrated unit that contains the flashing logic. Such things exist. You apply power, and it flashes.
- There is an IC under the white blob. This is a high volume but low cost production technique called chip on board or "COB".
I think #2 is more likely, especially considering the mass-produced high-volume look of this device. LEDs with integrated flashers are relatively rare and therefore expensive. A dumb flashing chip, especially without package, can probably be had for a few pennies in high volume.