NATO has certain standards, if the Hensoldt 6x24x72 meets those standards then the internals would be different.
Material that is not Mil-Spec can still be used by various military forces.
As an example, binoculars, the US Navy requires among many other things that to meet their standards the binocular model must be able to be submerged to a certain depth, in water with certain chemicals and be shaken at a certain vibration frequency for a given period of time and remain water proof in addition to the standards for resolution, clarity, color rendition, etc.
They buy lots of binoculars that don't meet that standard because they found they are good enough for the O's to gaze out at stuff with.
Most US military services have found that the O's end up with all the good stuff and the EM's who need the equipment won't get it, so they buy off the shelf, which is cheaper so that everyone can have something.
SOF's are different in that they try to provide all the good stuff to everyone.
Anyway, just because something isn't mil-spec does not mean the military isn't using it or a slightly beefed up version.
French Foreign Legion uses lots of Hensoldt, Swaro, S&B and Zeiss scopes that are not mil-spec per se but meet their requirements.