Once the remnant is in possession of the Gospel, they will "rejoice." What does that mean? What form would "rejoicing" take as a result of receiving the Gospel?
What does it mean to "know that it is a blessing unto them from the hand of God?" How would they recognize that?
What are the "scales of darkness" which cover eyes? How would the scales have been over their eyes in the first place? What does it mean to have the scales "begin to fall from their eyes?" Does "begin to fall" mean something about a gradual process, rather than a single quick event? How do scales continue to remain in place, even as they "begin to fall?" What does that imply about the difficulty in overcoming errors because of false understanding or traditions? Even the remnant will struggle to fully remove the "scales of darkness."
Why are there "not many generations" involved in this process? Do you need "generations" to pass away in order to fully remove darkness?
Why is it not possible to accomplish this in a single generation?
If the Lord's purposes in redeeming the remnant will take "not many generations" then why do we think we can accomplish it in one? How gradual a process is involved?
What does it mean to become a "pure and delightsome people?" (For many editions of the Book of Mormon, this phrase used to be, "white and delightsome." It was changed back to the original, "pure" rather than "white" in the 1980 edition.)
If this process is going to involve "not many generations" then how far away are we from this unfolding?
When we read prophecy like this, we should realize we are looking at unfolding history from the Lord's perspective. We want to know what will happen in our single lifetime. We are impatient. He is interested in having us know the truth.
Nephi's prophecy gives us a perspective that helps put our own time into context. We are in a hurry. History is not. There is a great deal left to do. There is a great deal left to happen. Nephi is letting us see this lengthy agenda.