Back again,
It seems my memory is a little hazy. Shorts were first introduced in 1905 for wear in tropical climates. However, at that time they were worn with puttees wound around the leg from ankle to below the knee.
This was the order of dress through WW1 although some scots regts, in kilts, abandoned their diced hose and spats and instead wore wool hose and short puttees.
But for the army in general hose tops and short puttees were introduced with the tropical uniform in the 30s.
So your picture would be from this period or later.
John915