Approvals or Selects?
Approvals: the client judges every photo — accept, changes or reject. Selects: the client only picks favourites, up to the limit.
How do I let the client pick again?
On the gallery's Selection tab press “Reset all picks” (or “Reset” on one person's picks), tick that you understand and confirm. The picks are deleted — this cannot be undone. A locked selects gallery stays hidden from the client until you turn off “Lock answers”. A reset does not count as a new question in your plan.