I know very little about military photos but I'm just going to venture an opinion which could just as easily be wrong.
I think your best way of determining where this was taken is to explore similar New Zealand Army photos of the period. I reckon there are plenty similar ones out there.
It seems to me that it is unlikely to have been taken overseas, as this was the kind of photo you took to leave for your family (of those I've seen a great many).
The ground he is standing on seems to be damp and with more growing in it for what I would expect in Cairo. It's not going to have been shot in Gallipoli.
I think the most likely place the pic was taken is likely to have been at a training camp at home. Do you know where they were?
Curiously the background (behind the tents) looks like a cliffside. It could just as easily be the side of a pyramid, but my guess is that's very unlikely.
Hope this helps a little.