User blog comment:Xilinoc/Ch. 568. Hear. Fear. Here 2/@comment-5693502-20140212122816/@comment-26420452-20140212180606

I think it's more about getting used to it. For example when I started watching the series, it was difficult for me to accept that a wolf (a dog to me) could be a captain or later on, that Aizen had been planning everything (still having some trouble with it).

So, after sometime I'll consider that it's most natural that Rukia can stop her metabolic activity and so can't be impregnated with fear through her skin, but the metabolism is just fine when it comes to the fear getting through vision.