[shutupalready]

> The tiny tab allows gravity to cause all the pullers to hang in the same direction as they fall into a rail toward the left.

The explanation above makes it sound like the pulls are getting re-oriented (flipped around) which is not what I see in the video.

I think a clearer explanation is this:

The pulls are aligned 50% tab-right (good) and 50% tab-left (bad) as they approach the feeder chain (or rail at the left as the OP calls it).

The tab-rights fit into slots in the feeder chain and proceed to the next assembly step.

The tab-lefts don't fit into the slots and simply drop away into the rotating pan below (from which they presumably return to the pot and make another attempt at the feeder later on).

[yeahboats]

I think its more that the tiny tab prevents it from falling through the rail, acting as a pivot. Gravity pulls the rest of it down.