From website:

NL4 - MINI CHRISTMAS SOCK

This ornament size sock is constructed same as the large CHRISTMAS SOCK. Good way to practice double pointed needles and after thought heel. One color chart is included.

SIZE: 6 1/2” around, 7” long

YARN: Heavy weight, 50 yds each of 3 colors

NEEDLES: Double pointed sz 8

From the original book:

This miniature sock knits up quickly in heavyweight yarn. Like its big brother, the Mix-and-Match Sock on page 60, it features an “afterthought heel.” You’ll knit the stocking straight down the toe and then add the heel afterwards, when you’re done. These stockings make great ornaments, or tuck a small gift inside for a special friend