Roper/Kenmore/Whirlpool Dual Action Agitator Only Spinning One Direction?

I repair appliances for friends, family and sometimes at work. I have run into a situation where I have come across several "dual action" agitating washers that only spin one direction. The bottom agitator does spin back and forth but the top just spins and spins in one direction. Is this how it's supposed to work? Growing up with an older Kenmore 80 series washer I'd often watch the top agitator spin back and forth. I thought this is how most all agitators functioned. It is my understanding if the agitator spins one direction then clothes and towels will get twisted up.

I filmed a short video clip to demonstrate what I'm referring to. I'm just looking for someone to either tell me if it's working properly or if not what might be causing the issue.

https://youtu.be/eCUPx1QvSBc

Any help would be thoroughly appreciated.

via Roper/Kenmore/Whirlpool Dual Action Agitator Only Spinning One Direction?
by Grunged