Numbers: How does Sort Now work and why isn't it sorting?

In Numbers, what does Sort Now do?

I'm having trouble getting the Sort Now button to work.

As you can see in the photos, I have the table set up. But, the Sort dialog box looks to be set up properly, but when I tap Sort Now, the table does not change the sort order.

Unless I'm misunderstanding how the Sort Now operation works as you can see in the photo below, how does the Sort Now button operate?

Thank you.