When you wrap your yarn around and then let it drop, you get a pretty openwork/droopy stitch. What they're having you do is...
1) add the extra length with the 3 yos in row 2
2) drop the extra yos by moving 6 real stitches at a time to the right needle - do step 3 below before moving on to the next batch of 6
3) move those 6 stitches back to the left needle, twisting them by moving stitches 1-3 over 4-6 and then knitting all 6 stitches
4) recover from all of this by knitting a regular row
The first time you let those extra loops drop is sort of nerve-wracking, but it works and it looks pretty in the end.