Most lamps push light down. The torchiere pushes it up. The tall floor lamp with its bowl-shaped shade pointed at the ceiling throws its light upward, where it bounces back down soft and indirect, filling a room with a gentle, shadowless glow. It's a specific idea about how to light a living room, and it belongs to a specific moment.
Indirect light, made modern
The torchiere came into its own in the 1920s and 30s, when indirect lighting looked modern and sophisticated. Direct light casts hard shadows and glare; bounce it off the ceiling first and the whole room fills evenly, without a harsh source anywhere in view. That was the appeal, and the torchiere delivered it in a single freestanding piece you could place anywhere without wiring.
Why it needs a big bulb
To throw enough light to fill a room by bounce alone, the torchiere needed serious output, which is where the mogul base comes in. Many torchieres take a mogul bulb, the larger, higher-wattage base, because indirect lighting is inefficient: you're throwing light at a ceiling and using what comes back, so you need plenty to start with. For a long stretch, high-wattage mogul incandescents got scarce, hot, and power-hungry, which left a lot of torchieres as beautiful, unusable objects. Period-correct mogul LED bulbs changed that, delivering the output a torchiere needs at a fraction of the heat and draw.
Salvager's Note: A torchiere that won't light bright enough usually needs a mogul (large-base) bulb, not a household one. A mogul LED gives the output indirect lighting demands without the heat that scarce incandescent moguls threw.