1. The ski is immersed in the snow. It can't skid, because the snow is up against it laterally. Therefore it has to be steered (carved). It's achieved by:
2. The initiating strong pole plant. That, in itself, is evidence that the skis will be unweighted (though the pole plant also aids the timing). The steeper and deeper the snow, and the more dense the snow, the stronger the unweighting will be.
3. The pole plant is synchronised with the flexion of the legs. At this point the upper body has sunk relative to the snow surface. The downweighting (and the skis are now at an angle to the fall-line) now provides the springboard for the extension of the legs.
4. The legs are now primed to extend and the thigh muscles now push the upper body upwards. This all happens in a fraction of a second, BTW.
5. As the upper body rises the skis become progressively 'lighter'.
6. At the point of maximum extension of the legs the thigh and stomach muscles are able to pull the feet upwards. This starts the unweighting.
7. As the unweighting occurs and the feet rise, they are able to steer the skis into the fall-line because they are very 'light' at this point. The upper body is now reaching its high point.
8. As soon as the feet have risen, the skis are steered out of the fall-line. The wrist primes the pole for the next plant.
9. The upper body now sinks again, and the pole is planted again, as per point 2.
I'm looking forward to reading of the first of you to commit to taking an instructor's qualification. I wasn't able to understand the above without going through the syllabus, training and practical experimentation. Go for it - it's a great investment.