You can see how I hold the yarn in my left hand, the dye has marked its path: over the index finger, under the middle finger, over the ring finger, under the pinky. There's dye on my thumb because I purl using my thumb and I was doing a K2P2 rib for the mitten cuff. (I know there are some other thumb purlers out there but I haven't met any in person.)
The first pair of Komi mittens are done, here's the final photo. I blocked one of the mittens inside out as the "Mostly Mittens" book suggests and it does make a difference. Not better or worse, just a noticeable difference.