my idea of Ni is that we do intense detail-work to revise and re-sketch our internal vision of the way the world works. it is a metaphysical system. the ability of our Ni depends on its accuracy which is nothing but the fit between our sketched maps of the world's essence and what the world actually is/is becoming. providing more revised structure and more closely attuned detail is what gives our Ni space more reality, more perceptiveness, more open-ended clarity of insight, of symbolic manipulation and essence extraction and linguistic pattern-recognition. of interpolative conceptual abstraction, in short.
Ne is different because it goes in the opposite direction, is skilled in the materialization of conceptual seeds and can see the path in fast-forward to actualization like a quick and to-the-point highlight video.