It probably doesn't look like the picture because your rib isn't lining up. To do that even with the increases, you knit the sts that look like knits and purl the ones that look like purls. On Row 6, the new stitches will make a 2nd purl st on the RS so you'll be doing a 1 k, 2 p pattern on the rs and on the ws it'll be p1, k2. After the incs on row 18, you'll be in a k1 p3/p1, k3 rib pattern. I'm not sure if it wants you to add a stitch at the beg and end of the cast on and work it in stockinette to use for seaming, or you could just seam the edge stitches as written.
sue- knitting heretic