looking at his uniform a couple of things that stick out
the uniform is late WW1 economy issue (no pleats in top pockets),
there are no collar dogs (prior 1922),
he's wearing khaki service dress with a tropical helmet, I think he has just arrived in the middle east and not been kitted out properly yet
the bayonet is very long, longer than the 1917 patt issue, i know the territorials used older equipment until being resupplied in france, I am not sure when the 1917 bayonet was updated but I don't think it was undated by a longer model
no medal ribbons visable
my tupenneth
chris