"The defendant positioned his body so that he appeared to be reading a book on top of the table. The defendant was actually looking at the mirror underneath the table," court documents stated.
Initially the then 54-year-old told officers there was a magnifying glass on the other side of the mirror which he was using to assist with reading.
In interviews with probation, Turoa acknowledged his behaviour was "wrong, creepy and sick" and said he did it because of stresses in his family life.
His lawyer Peter Eastwood said that the offending did not reach the threshold to make it an indecent act and that it should have been classed as offensive behaviour.
He also argued Turoa's former counsel "capitulated" when a judge told them there was no defence to the charge.
Justice John Faire said there was no miscarriage of justice and dismissed the appeal.
A spokesman from the Waipareira Trust at the time said Turoa had resigned from his position after being charged but the court heard how the defendant hoped to find work again after undergoing counselling.
The defendant was convicted of a similar offence in 1982, which involved alcohol and a friend's girlfriend.