After finishing row 10 of the chart last night, I compared the pattern side to the chart. Hm, couldn't make them match. Finally decided I was comparing light to dark and vice versa. Yeah, that's the ticket.
No, it's not. I had decided that I'd charted the chart backwards, and thus must knit from right-to-left...
and had knit the entire back of the mitten mirrored from what it should have been.
Somebody pass me a beer.