Since everyone is guessing around here, I will also offer my thoughts about this design.
This machine is
not german!
first - upright centre struts are
(nearly) nowhere to find here!
second - the setting!
Where or when should this picture have been taken then?
Before the war? - surely not.
(during the war I wouldn't expect to meet that many civilians at a factory roll-out and after the war constructing of new aircraft was prohibited, as well in Austria)
I would date this one in 1917 or rather later in a non-warring country.
The inline engine creates a german appearence but the clumsy front (with side-radiators?) does not make it look german at all.
But it migh be an influced design with a licence built or copied engine like some others in the far east (that also used Hall-Scott 6-cylinder inlines).
Does someone know "a big aeroplane factory that started to built aeroplanes" there at a time meeting our challenge?
(the ground looks pretty sandy and the airfield might have been newly prepared with gras seeds)
Another thing one can search for could be a country with a 3-colored flag.
Both wingtips are colored, most likely in national colors.
But I haven't found a possible candidat yet.
Cheers
Aquilius