Except as authorized by section 204C.15, a voter shall not reveal to anyone in the polling place the name of any candidate for whom the voter intends to vote or has voted. A voter shall not ask for or receive assistance in the marking of a ballot from anyone within the polling place except as authorized by section 204C.15. If a voter, after marking a ballot, shows it to anyone except as authorized by law, the election judges shall refuse to deposit the ballot in any ballot box and shall place it among the spoiled ballots. Unless the showing of the ballot was clearly intentional, the voter shall receive another ballot as provided in section 204C.13, subdivision 3, clause (d).