Talking about the teacher audience, it could be useful being able to share one move with their non-dancelib-users students.
This is an added value for the teachers (even more for the ones who teach alone)
a useful work material for their students
and also a way to promote Dancelib, with marketing messages on a 'publicly' shared move.
Pushing that further, we can link that to the referral program feature request, and the teacher could have a reward if someone subscribe through their shared moves. (But even without that, I think teachers can be interested in such a public share feature.)