The instructions drove me insane: what in the world does “knit in this manner mean”? So after frogging the short row start three times, I checked Ravelry comments and realized that the repeat on right sides is
slip one stitch, knit 1, yo, knit until marker, yo, slip marker, knit 1, yo, knit until two sts before end, yo, knit 1, ssk. Turn.
And wrong side rows:
slip 1, knit until one sts before end, p2tog. Turn.

So if one row is
“s1, k1, yo, k3, yo, sm, k1, yo, k3, yo, k1, skk” the next right side row is
“s1, k1, yo, kX+2 (=5), yo, sm, k1, yo, kX+2, yo, k1, skk”

The pattern is simple if it were only explained simply. It drove me crazy not seeing right away where are middle was and why the instruction didn’t tell you how to slip the marker. Without telling, the marker moves due to the yarn overs so make sure it is always one the right side of the center stitch looking from the right side. This makes life easier.
And according to my logic, if you start with the right side and knit 34 sts to start the scarf, in the end you need to finish the RIGHT side (not the wrong side) in order to have the same amount of rows on both sides.
AND for symmetry’s sake: start with KNIT 31, then scarf…

Summa summarum: it turned out really cute. The size is just right and this was good use for this yarn that I had just one skein of.