You are slowly traversing across a slope from left to right. That means your left leg is downhill and your right leg is uphill. The weight is mostly on the left, downhill ski. The right uphill leg is very light. Now you want to make a left turn. What do you do??
OK. I'm really bad at this...
I cannot be sure about the exact timing, but this is what I think I do. I can't tell from the video if I am doing this or not.
I'm picturing a GS turn with lots of space.
I'm not yet at "fall line", if my weight is still on the downhill ski. I am still finishing the previous turn.
My left arm is probably a little bit back (ideally, should not be), and the pole tip is starting to swing forward and downhill, toward the next plant point, which shifts my torso and pelvis more to the left, but the weight shifts more to the right foot, evening them out. (I'm thinking this is the bit that sounds odd to you?) Right arm is a little bit forward, having just pulled out of a pole plant; because the pole is too long, the right arm often gets dragged/pushed backward, which pushes the left arm forward, which is what I want anyway. (The lower to the ground I am, the more the right arm would get bounced backward, as the poles become about four inches too long at this point.)
As I cross the "fall line", or the end of this turn and the beginning of the left, the weight is even between the feet. (The frame with the super wide stance above.) The legs are at their straightest and are even with each other. The skis are not edged at all. Pelvis is parallel to the ground. Torso is perpendicular to the slope. Ideally, my arms are closest to their neutral position, the right arm maybe lifted up a little to avoid dragging the poles (which I could achieve by flicking my wrist more, too), left arm pointing down and forward toward the next planting point.
Left pole touches or plants at this point and more of the weight goes to right ski, and I begin to really turn. I start to incline inside, i.e., downhill, leftward. On crud, I bounce "up" a little with the pole plant, and use the movement back down to power the pressure on the right ski (or both skis in powder).
On flats, I do not seriously transfer weight to the right ski until I'm about 30 degrees uphill from the peak of the turn (peak of the turn being when I'm pointing down the hill.) Sometimes I am late, but the transfer is usually done by the peak. On crud and powder, I try to do this sooner, 60 degrees or so, making it feel like I am kicking up hill, but it's really down into the snow, giving me a firm footing and bending the ski, making the tip and tail point up more, for more float. The right ski is now seriously bent and turning. The left ski is just dragging along for the ride, but it's unedged, so rotates easily, unless it's really cruddy.
Ideally, the torso faces the same direction as the right ski, but is tilted inward, to the left, downhill.
On groomers, I press against the inside/left edge of the right ski. On powder, I press against the base of the right ski.
At the peak of the turn, when I am facing downhill and for a little bit after that, 70-100% of the weight is on the right foot. All on the ball on flats, even or more on the heel on crud and powder. Left ski is not edged, and can rotate freely. At this point, in crud, if the left foot drags a little bit and forms a wedge, or gets caught on a track, it gets picked up off the ground. On flats, the left knee is bent to 90-120 degrees, depending on how strong I am feeling and how fast I am going, right knee is almost straight. On crud and powder, they are more even. Still, left knee is always bent more, and is more forward. Skis are at their farthest apart. Left ski is usually more forward. The left arm is still bouncing up from the pole plant. (If I keep it up, or pretend that it was bounced up, then I have my infamous arm lift.) I have no idea what my right arm is doing at this point; probably neutral and a little back.
After the peak, there is sometimes a moment of uncertainty, in which case I traverse while keeping the weight on the right foot. If there is a skid or mushy powder there is even more pressure on the right foot to keep the edge. If I'm losing the edge on the right foot, I shift to the left foot, but without changing the posture. If the terrain is really uneven, I even out the weight between the skis, and lower my upper body more; skis come closer together, and I traverse until I feel secure on both feet. If I feel secure enough, the right arm starts to go forward and the weight shifts toward neutral. The skis come closer together, although on crud and powder they often stay apart (like in the video) for left-right stability.
Before I return to the fall line, the right arm starts to move forward...
And so it repeats.
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Alternatively, from the position you describe, I can simply transfer all weight to the right ski. The right ski will flatten out, then edge to its left edge, and start to turn. The movement of the boot flattening against the snow pushes my torso to the left, and I press against the right ski's new edge to then shift my torso to the left. The knees never really straighten out, as I'm squatting at fall line. This is murder on the thighs, as they are doing all the work of shifting the weight, so I do it only if I have to rush it.
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Every time I reread this I'm finding a typo, so this might be completely jumbled up. And, remember, poor proprioception...
Whenever I take the weight off a leg it tends to want to hang in its natural position under my hips - where it would normally be when I'm standing or walking.
I think my inside leg takes this literally, under the hip as in as the ball drops from my hip, as opposed to hip-width from the outside leg. (I try to keep my pelvis parallel to the ground.)