It was an aboriginal light horsemans study.
Well, err, may I just mention the following

re the James FIRTH on that Ancestry tree

1837 Muster as per BDA I read:
December 1837
James FIRTH, age 26, convicted Tipperary, arrived per Eliza in 1832, Ticket of Leave in Bathurst, and he was assigned to Robert SMITH.
From the Convict Indents I read (others may read differently, this is just my transcription)
James FIRTH, aged 22, Read and Write, Protestant, Singles, from Co Antrim, a Tailor (5 yrs) Soldier , Steal Cloak, Tried Tipperary, 16 March 1832, 7 years, no previous convictions, 5 ft 7, Ruddy and freckled complexion, Brown hair , Chesnut eyes, no particular marks or scars… So I wonder about this chap, a soldier and a tailor … Walter Sherry was a tailor in Mudgee when Agnes and Mary were there as girls….
So far, I am becoming doubtful as to how that photo could be one of a grandson of this particular James FIRTH.
Cheers, JM