The natural tendency for any locally derived and accelerated gas path that must re-enter a still mass is to curve. This does not apply to an energetic path that is parallel the direction of entry of the wing. . .
As the upper biased flow spills off the tip, it curves, and contacts the flow off the bottom, which is curving also. The two flows are discrete, and compliant with Newton (#2), wish to maintain their cross section shape. There is no choice for them but to entwine....(Bernoulli, as matchmaker). Unbound, they expand, whilst gradually losing definition, and eventually all memory of their originating shape.
Will that suffice for a description of vortex generation via the Oxford genius?
I thought not. Anything at all useful?
As the wing collects, contains, and deflects (directs) air, can we then call it a 'nozzle'?