An essential component of the pancake is *anterior pelvic tilt*. OK: that's a concept—let me explain. If you cannot move your pelvis forward, at the same time as the back, you will be bending in the back, and not at the *hip joints*. We see this all the time, and sometimes even in people who are teaching how to do the pancake.
It is this 'how do I move the pelvis?' aspect that many people struggle to master, even people who are relatively flexible in the other muscles involved in the movement (so hamstrings, adductors, etc.). In this sequence, Liv explores a variety of techniques to learn how to feel how to actively move the pelvis – "actively" means using muscles in the hips and the groin to do the movement, rather than bending in the back.
The main problem people make is they get into their best pancake first, before trying to move the pelvis—and then, because they're in the stretch (and everything is under tension), they find they can't move the pelvis at all. The secret is to back off out of the end position and feel how to move the pelvis when things are more relaxed. Counterintuitive, perhaps—but it works.