Carry the yarns up the side of scarf between pairs of rows?

[asy88]

I am thinking about knitting the Fizz Eyelash & Cotton Chenille Scarf. I am a little confused about the pattern. I think i start with one yarn and do two rows in garter stitch and then switch to the other yarn and do another two rows in garter stitch. what i don't understand is the "carry the yarn up the sides of scarf tween pairs of rows". what does that mean? how do i "carry" up the sides? please help.

[amy]

You just stop knitting w