This has reference to the eight witnesses and Mary Whitmer. The eight witnesses, as described above were allowed to handle the plates and view the characters. This is in contrast to the three witnesses who did not handle the plates but had the pages turned for them by the angel Moroni (see commentary on how the 3 witnesses received their witness)..
The story of Mary Whitmer is interesting. She had been making great sacrifices in the Whitmer home to allow the work to progress. One day, while wearily performing her labors she saw the angel Moroni who showed her the plates. The story is told by her daughter who had inquired of Joseph as to the location of plates:
"I saw something which led me to the belief that the plates were placed or concealed in my father's barn. I frankly asked Joseph if my supposition was right, and he told me it was. Sometime after this, my mother (Mary) was going to milk the cows, when she was met out near the yard by the same old man (judging by her description of him) who said to her: 'You have been very faithful and diligent in your labors, but you are tired because of the increase of your toil; it is proper therefore that you should receive a witness that your faith may be strengthened.' Thereupon he showed her the plates. My father and mother had a large family of their own, the addition to it therefore of Joseph, his wife Emma and Oliver very greatly increased the toil and anxiety of my mother. And although she had never complained she had sometimes felt that her labor was too much, or at least she was perhaps beginning to feel so. This circumstance, however, completely removed all such feelings and nerved her up for her increased responsibilities." ("Report of Elders Orson Pratt and Joseph F. Smith," Millennial Star 40 (9 Dec 1878):772-73 as taken from Testimony of the Book of Mormon Witnesses by Preston Nibley)
It is remarkable to note that Mary Whitmer was the only woman to behold the plates. Even Emma, who acted as a scribe and was an untiring support of Joseph's work, never saw the plates unless they were covered in some way. The only members of the prophet's family who ever saw the plates were Joseph Smith, Sr., Hyrum Smith, and Samuel H. Smith who were only allowed to see them as part of the group of eight witnesses.