The guy is taking the Christopher Radko bubble lights and adding LED illumination to them. LEDs by themselves will not provide enough heat to bubble the tubes. That's why he added a resistor heater. The real reason, I speculate, that he added the LEDs was firstly to experiment, and secondly, to get his bulbs lit because he said they were all burned out when he got them and, as he probably discovered, the original size and configuration of the Radko bulbs are longer available. The entire Christopher Radko bubble light series has reportedly been discontinued. I don't particularly like LEDs to light any antique lighting or newer bubble lights because the light is blue-white while the ambiance orangish glow of incandescent lighting is missing. Additionally, you cannot control the brightness of the LEDs with a rheostat. For the record, the Yorkville, 10 watt, 120 volt, T6, candelabra #10360 is a direct replacement bulb for the Radko series if you can get by the round top instead of the flat top as was originally provided in the Radko bubbler.
Randy Pozzi