As I recall, the performance on the sitar (Obviously dubbed in by a real sitar musician) has such sexual intensity, it is almost palpable, especially since she is a young woman performing in front of her father and another young male. The sexual overtones are obvious. Also, the sitar music probably evokes bad feelings in her father who knows the tragic truth of her daughter's curse. Another consideration is that while she is playing, you hear the mysterious music which always precedes death via transformation of Anna into a snake. Since this is happening as indicated by the mysterious music, she is also in the throes of the changing into the Reptile and as such may appear threatening to her father.
