He also denied "judge-shopping" and said he was only acting on instructions from his client.
The complaint was investigated by the Standards Committee, which found Mr DH had attempted to shop around for a judge and was unprofessional in attaching the picture.
It censured him and ordered him to pay a $2000 fine and $500 in costs.
Mr DH asked for a review of the penalty from the Legal Complaints Review office.
Review officer Dorothy Thresher said Mr DH accepted that on reflection, he could have attached a different picture "that could not have been misconstrued".
"Mr DH emphasises his view that the picture was intended to be a 'cheeky humorous token', and says the penalties imposed are manifestly excessive."
But his actions in attempting to request a particular hearing date when a specific judge was not sitting would not help "maintain public confidence ... because it served to undermine the legal system within which Mr DH was providing legal services", Ms Thresher said.
Sending a picture of a monkey was taking "a risk that did not pay off and was completely unnecessary", she said.
The penalty of censure and a $2000 fine was upheld and Mr DH was also ordered to pay costs of $1200.