Otago University epidemiologist Professor Michael Baker said while he couldn't comment on if mask-use was kept during other parts of the day, it was disappointing to see "leaders not leading by example".
"There is an added responsibility for our leaders to wear masks when being photographed or in public settings to lead by example, this was a missed opportunity to normalise mask-use," Baker said.
The photograph for today's Youth Parliament events also ironically coincided with an email this afternoon from the Speaker of the House Trevor Mallard.
He reminded those working at Parliament to wear masks and added: "It applies to everyone."
"It has come to my attention that some people are not wearing their masks when moving around the public areas on precinct, and are ignoring security when approached about this," he wrote.
Mallard said only "a couple of members/staff" had a medical exemption.
"Everyone in these buildings should be wearing their masks when moving about. For the safety of all on the precinct, I remind you of this rule.
"It applies to everyone. I have asked the CE of Parliamentary Services to advise me if anyone is not cooperative."
Mallard told the Herald his email was not in response to the youth parliament events.