Redaction analysis: The break between verse 7 and 8 is dramatic. It is just as dramatic a break as the one which introduced chapter 11. In the 1830 edition of the Book of Mormon, there is no chapter break at this point. In that 1830 edition, there three initial paragraphs, each beginning with "And now..." The phraseology "and now" is used and a ligature in event lists, or in non-verbally connected paragraphs. Thus "and now" is used frequently in Nephi's historical sections, and is frequently combined with "it came to pass" when the ligature also requires the passage of time.
In this case, there is no historical passage of time, there is only a conjunction of topics. The first "and now" of our current 2 Nephi 11 (1830 2 Nephi 8) marks the declaration that Nephi will shift topics, and forms the ending of the recording of Jacob.
The second and third "and now" clauses identically introduce Isaiah. Thus it appears that Nephi recognizes his departure from his original purpose, and now returns by repeating the opening clause. Thus 2 Nephi 11:2 and 2 Nephi 11:8 begin identically, and end thematically similar. Both are Nephi's intended introduction to Isaiah, with his testimonial aside intervening in his original purpose in writing.