This is a very nice photo of Cornelius (Con) & Tom O'Brien. Cornelius was an infantry man in the 28th Maori Battalion. He is listed on this site as being in C company but his group photograph at the museum of New Zealand has the title "G company", 9th reinforcements. Tom O'Brien was in the tank corps. Con is on the left and Tom is on the right.
This photograph was in the photo album of Sonny O'Brien (now deceased), Con's brother. It is now in the possession of Sarah Smith, Con's niece.