Below are some close up pictures of the circuit board from both sides:
On the side we have the connector mounted there is a wirewound inductor a couple of resistors, cap and a LED
On the other side we have 3 components with top markings:
- B14 is a schottky rectifier like MBRS140
- E2HD is a switching transistor like FDV305N
- STVD is a boost controller like S8352
As for the small RC circuit and LED it seems that since the regulator runs in PFM mode when there are sufficient cycles of charging the output the cap has enough charge to light up the LED and hence indicate a load. The LED lights up whenever a load is connected.