Challenge
It is not a show: it is the recruiting mechanism that feeds the other formats — someone proposes a challenge, people sign up within a window, the audience backs them and the proposer selects.
What Challenge is
A Challenge does not broadcast anything by itself. It gathers people and ends by choosing which format the result happens in: Match Show, Arena or Blind Live.
It cannot become an episode of itself, and it does not lead into a Cast — a Cast is born from its own application funnel. Those two exclusions are structural, not a rule someone has to remember to apply.
Audience backing only adds
The audience backs; the audience does not reject. A negative vote does not exist — it is not refused at the door, it is impossible to represent: there is no field for value, weight or direction anywhere along the path.
Backing does not rank anyone either. Participations are not comparable by popularity, and who backed whom is never revealed. The only backing you find out about is your own.
Why you sometimes see a state instead of a number
The backing percentage only appears from 30 participations onwards. Below that, a number would give false precision: with eleven participations, a percentage looks like a measurement and is not. In those cases you see a qualitative state of the interest.
If you signed up and have not heard back yet
"On hold" is not a public queue. You see your own state and nothing else: there is no position, no count of who is ahead, no count of who signed up.
Everyone gets an answer at the same time. The selection is settled in one go, with the same instant recorded for everyone — nobody is left without news because they were not chosen.
Entering a challenge does not reveal you. If your profile is anonymous, it stays anonymous in the list the proposer sees.
The vocabulary
No Challenge screen says rejected, refused, lost, eliminated or nobody chose you. The state of whoever did not get in describes the SELECTION, not the person — and whoever proposes can only point to who gets in, because the rest is computed by the server.