Is it open in the front or a pullover? If a pullover they could mean both sides of the neck at the same time. OR if it has an open front it could mean you're making both pieces at the same time, perhaps on a circ ndl (or 14" if the item is small enough for that length to accommodate all the sts).
Do you have a link to the patt or a pic? Is it the patt at lower left of this page?