Hi Anne, That's a good question! It's also a difficult one to answer given schools teach the "Pelvic Lift" differently. We specifically asked Monica to teach this exercise because she teaches it in its classical form (as taught to her by Romana Kyrzanowska) and because we know it is a confusing exercise to many.
The closest thing I learned to this exercise in my trainings was called the Pelvic Curl which involved a similar start position, but also curling much higher up in the spine. In that case, the head rest in an elevated position puts more pressure on the cervical spine, which could potentially pose problems for certain pathologies.
Thank you for questioning what you see and hear in our videos. We all benefit from the inquiry!