I don’t think I’ve seen a LED fireglow lamp before!

The heat from the incandescent lamp used to make a fan like wheel spin which created a shimmering effect, with LED giving off very little heat that effect will no longer work

We used to have a couple of fires with that wheel that hung above the lamp. Took a minute or two until the wheel began to spin. As you say, the LED version won't have that effect.

Grandparents had a gas fire with 2 fireglow lamps under a GRP representation of burniung logs and coals. This particular fire had B22d-3 lampholders and as stated by others above, the little thermally operated, spinning wheels to give the effect of flames

The B22d-3 lamps were a ploy to get you to purchase inflated price lamps, eventually they moved to BC and I have seen a few in my time that have used a pearl GLS, not very warming.

I have an LED fireglow that was used in my mum's fire, the spinner on that had already stopped working so it didn't matter that there wasn't the heat. I also have a couple of electric fan heaters with a glow effect. Both use a small motor to power what I can only describe as a 'long spinner'. One takes standard GLS lamps, the other has built in LEDs that are colour selectable. I rarely use them for heat, especially at current prices. But they do give a nice effect.