What's the significance of the 'w' finger position in Elfen Lied? I've noticed that in the opening sequence, and the big climactic moment at the very end of the season, Lucy has her hands on the figure's back with the ring/middle fingers together and the other two fingers separated in a 'w' sort of shape.  

Is this a symbol of love, a reference to Gustav Klimt (like the paintings) or something else? 

I've also noticed it on the cover of the 3rd Vampire Bund Omnibus.
It's likely to be a homage to the work of El Greco, who used this hand symbol in his various works.
Like this one titled The Gentleman with His Hand at His Breast

or Christ Carrying the Cross

The meaning of this gesture is subject to much debate...
Some hypothesis indicate that:


The hand gesture is a secret sign indicating that the gentleman is a Marrano -- a crypto-Jew who accepted Christian baptism in order to remain in Spain after the Catholic Kings' order of 1492 that all Jews leave Spain;

The gesture indicates a Loyolan/Jesuit spirituality that calls for the sinner to place his/her hand on their chest after committing a sin as a sign of moral pain. Both of these theories have been discussed at length in academic circles without, however, formal acceptance of either, though at least one academic allows that the hand &quot;assumes the function of an important communication, a personal avowal.&quot;