Yup, that's part of the "bring limbs closer into the center like a figure skater" advice. The head and core form the center of mass when tucked together, and whipping the arms back then pulling in as you whip the legs and jacknife them in towards the core adds extra rotation to that center of mass. When the head is thrown back away from the core and the limbs drag, there's no center and no added rotation.

The head is one of the heaviest parts of the body, so it's definitely worth pointing out, thanks.