Took a bit, but I found it - Yaarn is the name of her blogwhere the pattern is. Anyway that does seem like an odd way to write it.
" On the right side, knit the knits and purl the purls. On WS, purl the knits and knit the purls. " Usually this means to do that as the sts appear, but I wonder if she means as you did the stitches on the previous row.
The boxes that outline the heart should show as purls on the RS row, while the rest of the block is in stockinette stitch. At least that's what the pictures look like in the finished projects on Ravelry.