Thanks for all of the perspectives, so far.
It's not necessarily easy to determine if dancers are giving proper weight.
The butterfly whirl is one of those moves especially where bad weight is common, and the move can be really uncomfortable:
- the person coming out of the allemande scoops at the waist, rather than shoulderblades - the arm is below center of mass, and can cause lower back pain. And really, I don't think hands belong on waists in any contra move.
- the person getting scooped up puts hand on top of shoulder / doesn't connect with their arm at all. This is probably the most frequent issue I see / experience dancing. And I believe it's exacerbated by the "gents do the thing to ladies" framing of prompting. And it's why I very much agree with those who've replied emphasizing the use of neighbor/partner.
- as mentioned by others, the person getting scooped not moving forward, and relying on the allemanding person to drag them along. Again, the "gents do the thing to ladies" exacerbates this, in my opinion.
And these above difficulties aren't always easy to spot from the stage.
So I like the "scoop" as a descriptor of the motion, but I am not really sure if it's the best descriptor of the *connection* between dancers and the shared weight. It's probably fine with a clear walk through - I'll often pause and emphasize connecting at shoulderblades and moving together as a unit.
I wish there was something slightly better that worked for both, but all of this discussion has been really good to reevaluate my teaching on these.