Can anything be gleaned from this photo...

[Lachlan]

The glengarry is interesting. The RSF wore diced glengarries, with plain being used by pipers.

As for the studio photo, photographic studios often carried props which could be used by customers being photographed, to pep them up a bit. As a result, you sometimes find incongruous combinations which causes consternation to modern researchers (though not in this photo).

I remember a studio photo of my dad taken in 1942, wearing his utility battle dress and shoulder slides of the Royal Corps of Signals. Instead of a forage cap with the "Jimmy Signals" cap-badge, he's wearing a khaki peaked cap with the badge. Totally non-regulation, but more impressive in a photo, the peaked cap he donned was a photographer's prop, onto which my Dad substituted his Signals badge.