Griffindor illusion scarf

I searched for help on this scarf in case it was answered previously but haven’t found anything. I am just confused about the chart key in the pattern:http://www.the-leaky-cauldron.org/features/crafts/knitting/gryffindorillusionscarf-2

Key:
orange square-knit in mc
orange square with an ‘X’- purl in mc (even rows)
white square- kit in cc odd rows
white square-purl in cc even rows
white square with an ‘X’- knit in cc (even rows)

I am not sure if this is suppose to be stockenette stitch or not? I can’t tell by the picture. What I am confused about is the yellow is a alternating knit, purl, but the red is not? Can someone clarify for me?