Sandman and others got that one right. It is a mechanism to ALTERNATELY LOAD THE HIPS AND THEN THE SHOULDERS LATER IN THE SEQUENCE
Bonds drops the box and tips the bat to SS.
At that point he is shifting his center of gravity and coiling his hip back
You cannot load the shoulders when the box is dropped. so...
The hips begin to rotate open into foot plant as the box is lifted.
NOW...the shoulders load back( scap load) as the hips are opening accessing torso torque just at heel drop....overlap
He captures the most dynamic torque.
It is a mechanism to be timed ; not a timing mechanism
If you can time it you WILL hit it farther.