"participation" or fairness only really makes sense as something a talent would want. audiences do care about that a little bit, but not to the extent that it should be selected for. going from the hint that this stage tests pure skill, and that juna had the spark the main P lady was looking for in the audition... my guess that this stage has something to do with rewarding the fans that she just got? if this stage tests fansa, that would make sense why the group leader girl got juna in the group, cuz juna is gonna attract a crowd of fans who were casually interested in her who the other girls can win over. so basically it tests fan loyalty. thats my guess.