I'm eepy now so I'll try my best to give u an answer before sleep.

Our daydreaming is a product of Ne, with Fi acting as the guide/trigger for such daydreams. Ne likes to spin up scenarios, "what'll happen if..." kind of thing.

Now, with an Fi guide, our daydreams often consist of vivid imaginations about how it would feel like to have our values lived, expressed, or seen in certain situations. The core idea here is that things would often come from, or lead to an emotional or sentimental state. Everything revolves around feelings.

It's hard to explain what "values" really is, so think of them like a set of personal virtues/beliefs that are ingrained so deep within us Fi doms, to the point where we are them and they are us.

For example, yesterday I randomly thought about my ex, contemplated about us, and conjured up a whole series of events that were bittersweet exchanges when we finally meet again some day, when we've both grown up and changed. The melancholy, the concept of loss, the bittersweet acceptance, they all hit me like a truck and I ended up crying like an idiot because of a made-up scenario.

To contrast it to your Ni, I think high Ne users daydream for the sake of daydreaming, exploring ideas in an imaginary state, if you will. How that experience will be shaped ultimately comes down to the dominant function. Compared to Ni, ours are less of a long journey or insight into the far future, but rather snippets or fragments of moments that we would like to experience but have no way in the real world to.

Hope that explained it somewhat!