(Sorry Fe users; I know this post will likely sound hokey to you. )
So let's more deeply imagine Fi as the clay, Te as the wheel, Ni (or Si) as the hands. When you have hands and a wheel first - the tools - then are presented with the clay, you have established already some context with which to work the clay. Yet if presented first with clay, a great chunk of it, but no tools, what must one do to turn this mass into something that has a recognizable form? One must look around, see what's available to work with, develop proficiency to even start getting that mass of Fi shaped into something visually appealing to the world.
So the step beyond all that is to realize that Fi is not only a source material, the clay, but it is one of the tools too.
You say that "the inner light is too intense to resolve into an image for others to see" - what I am trying to say is if that inner light is Fi, one must find the way to reveal it to the world, not through working it to become what you think it should become, but transcending that, letting it both shape and be shaped. Letting it both be the light and what is revealed by the light.
Struggling to put that into words, but will work more on this.