Right elbow to cock left wrist?

[comdpa]

I was scrolling thru the recent 12-5 discussion when I came across a statement Yoda made:

A hitter uses the right elbow to cock and uncock the left wrist.

For the life of me, I can't figure this out.

Anyone?

This can be found in 7-3 of the book if you have it.
To figure out what Lynn was saying:

1) Take a baseball grip
2) Split the hands as far away from each other on the grip as possible
3) Keeping the left wrist PASSIVE, now just bend the right elbow, notice how the left wrist responds as a result.