In this interesting video, the bielorussian guitar player Tatyana Ryzhkova talks about her fingernails shaping.
Tatyana uses a right hand posture rotated outwards, and this implies an asymmetric length of the fingernails, with the index fingernail visibly longer than the other.
From her website:
Tatyana Ryzhkova, born in 1986 in Belorussia is one of the most promising young guitar players of the world. Meanwhile, she has the highest click-through rates on YouTube among the classic guitar players. In more than 400 concerts on all continents she won a large fan community due to her fascinating life performance with a combination of virtuosity, emotional dedication and friendly conversation.