The video Kat posted is NOT Joni and, while nicely enough done, not especially remarkable. Standard tuning, straight-ahead simple key-of-G chords, fairly basic pattern-fingerpicking.

Not bad at all ~ very nice vocal ~ but certainly not likely to help someone who'd "still like to see Joni's hands go through the progressions to see if I can pick up any nuances, particularly her right hand."

If Joni plays Libba-Cotten-style (upside down and backwards), I was never aware of it. I always assumed that the only reason I could never figure out just what she was donig was her penchant for multiple exotic alternative tunings.

Maybe YouTube had the real Joni on display when Kat posted the link, and responded to copyright complaints by substituting another video of the same song performed by someone less famous and less, um, nuanced.