If punchcard ballots are used for vote by mail voting, the ballots shall be marked by pencil, or by a marking device that enables the voter to register his or her vote by punching or slotting the ballot card. Counting of punchcard ballots marked by pencil may be as with paper ballots, or a true duplicate copy of each ballot may be prepared using the same procedure as provided by Section 15271. Vote by mail voter ballots so prepared shall be counted by the counting device.