Narrative analysis: From the standpoint of the story of Nephi, we have just finished his great epiphany, and now return to the theme of the development of Nephi as a leader of men. We began with a Nephi who was a younger brother, and have seen him develop as a leader based on his faith in the Lord. The incident with the brass plates put him in the unique position of being the leader of his older brothers in a specific task, which (although clearly with a spiritual import) an essentially physical labor.
At the end of this vision of Nephi, he returns to find his brethren disputing among themselves, not having clearly understood their father's dream. This episode begins to demonstrate the spiritual domination by Nephi over his older brothers. Just as with the brass plates, where the younger brother should not have been the leader, so too in things spiritual it should have been the older brothers explaining the vision to the younger brothers. Again Nephi goes against that tradition, and provides the answers for which the brothers searched.
Scriptural analysis: Verses two and three underline a very common problem in the world of scriptures. It is quite easy to have multiple opinions, and to discuss them vigorously. Nephi says that his brothers were "disputing" the meaning of the vision. It is easy to see among all of the various flavors of Christianity that this ability to "dispute" the visions and revelations from God is universal. Nephi provides the ultimate key. The key is not in further scholarship. The key is not in new found manuscripts. They key is not in esoteric analysis. The key is that these things are "hard to be understood, save a man should inquire of the Lord." Ultimately, our understanding of the things of the gospel will depend upon our understanding and communication with the Lord.
Of course this is not to say that study of the scriptures is to no avail. It only highlights that study in and of itself, without the guide of the Holy Ghost, can lead to various disputations, none of which would have the weight of the truth on their side. Of course this also is not to recognize that there are many who would profess to have done so, and still to dispute. The solution remains the same. The true doctrine, the true meanings, can be found only in correctly approaching the Lord.