To me, this is quintessential oriental dance posture:
Quite a few of my early teachers taught something that I think came from west coast tribal. Instead of standing tall with the upper body leading most movement, the teachers looked more like they were leaning back on their heels with the knees visibly bent like they are about to sit on a stool. I think this is what Hadia was criticizing.
For example the photo below shows a "before" and "after/corrected" posture. I would say the "after/corrected" is too bent at the knee, and notice how the dancer is leaning back. Probably all her weight is on her heels, and her rib cage is not slightly forward of the pelvis. Perhaps this is considered "ideal" for tribal belly dance (?) or vintage oriental/ am-cab whatever you want to call it, but it is most certainly not ideal for Egyptian dance. This would have Yousri sharif or Shareen el Safy whacking your butt with a paddle (figuratively speaking) and telling you to stand up straight.
Posture Before and After - tribe.net