This slide was shown to cinema audiences at the end of intermission- paid for by the Labour Party as part of their campaigning. Most political parties used the cinema for electioneering and these slides provide a glimpse into elections long since decided.
Given that this slide says 'Thanks to Labour' it was probably made when Labour was in government. The fashions suggest that this could have been at the end of Walter Nash's term in 1960- although it may have been for the 1949 election when Peter Fraser was in charge.
What is really interesting about this slide is it's definition of 'everyone'- a close look at the faces shows a range of ages and a mixture of men and women. However, there is no cultural diversity in this smiling constituency. It is true that Aotearoa has become more diverse in recent decades, but even when this slide was made its photographs did not represent 'everyone'.