Which one of my multiple assumptions is correct?

I also have found a video of a similar looking, but possibly different Westinghouse position indicator (though the one in this video doesn't seem to work correctly): https://www.youtube.com/watch?v=yFjLRkqfZOo

I assume the one in this video is an IEE/projection indicator (non-mechanical, an individual light bulb for each floor)? The fact that it didn't light up at one of the floors would also suggest this (unless that is because of a different reason). Or is it also mechanical, but the light turns off when the number changes, thus you can't see it mechanically move?