Oh wow, this is a neat one. I noticed this pattern when it came out, but didn't really pay it much attention at the time. Looking at your sock, and rechecking the pattern, it looks like all the twisted stitches do a decent job of breaking up the colour in a short-segment variegated yarn. That's pretty groovy.
And I love that colour combo; reminds me of the beach. Your recipient was lucky, hope they enjoyed 'em!