I wonder if Old Navy gave that description to discourage anyone from trying to figure out the pattern! ha ha Little do they know that they have thrown down the gauntlet for every knitter to try to figure out how to make a similar scarf!!! More than likely, the reverse is true: they probably adapted their knitting machines to a pattern that a real life knitter made!
I noticed this in their clothing lines and fabric...
I looked at the patterns you guys have suggested and while it might not be exactly the same, it is close enough for even an intermediate knitter like me to try! Cool--and I like the pompoms at the end a lot! I know I can make those!
Good luck with your scarf--I know you can do it--remember to post your final project!