The photo is from the New Zealand Police Gazette in 1918. John Mathieson, a discharged prisoner, is identified in the publication Onward as this serviceman.
When John joined up in 1918 his address was given as “His Majesty’s Prison, Invercargill”. He was a labourer from Woodlands in Southland and his next of kin was his mother Mary Tuffley, living at Woodlands.
John had a illegitimate daughter, Irene Guardian, born in Dunedin to Doris Gaurdian in 1917 and in the care of Doris’s mother. John left on a troopship in October 1918, but of course by the time he arrived the fighting was over. He spent five months in hospital in England before returning to New Zealand in 1919.
In 1926 John married Mary Ann Seator. He died in Invercargill hospital in 1958.
Source:
Photo from Onward: portraits of the New Zealand Expeditionary Force volume 4, by P J Beattie and M J Pomeroy, 2017.