Aaah, okay. It is probably curling up a bit too much so you can't see it. I can sort of see the difference, but unless it is stretched out, it is probably hard to see.
This isn't the same as what you are doing, but if you were doing one row knit, one row purl, it would look something like this:
The little V shapes on the "right side" are knits, the upside down U bumps on the "wrong side" are purls. But they, as mentioned before, are the same thing but from different sides.
