The Up|On Lamp has some special switch inside which only lets the bulb that is on top have electricity – as you can see from the video, if you hold it upside down, all of the bulbs fire. To shut it off, you flip the handle to the top. What an interesting lamp!
I’m not sure as to the type of lamp that is included with the fixture – my assumption is that any will work, but the filament on the included lamp is pretty sweet. However, you know about the word “assume.”