The difference between an Exhibition Challenge and other challenges is what happens once it ends:
For Exhibition challenges, photos are selected to be Printed or Digitally displayed in an art space (i.e. Photo Fair, Art Fair, Art Gallery).
Photos that appear in these Exhibitions have a chance of being sold and you receive the earnings.
*Important: You must complete the application form prior to the challenge end.
Once the payment has been completed, there is no other form to fill in :)