Hi Amy, Each person will have their own experience in their body and how it feels. I cannot tell you a "should" feel. The cue is designed to place one's attention on the sacrum and how imagining how the bone responds to the movement of extension. I do cue this in all prone work.
Also interesting knee stretch with the interval rotation I RELLY felt that and I’ve never done the hip glide with the knee stretch before - love to learn something newÂ