Yasurime styles

[Strider]

Please forgive me my ignorance, but I have a silly question concerning the direction of file marks on nakago. I was looking at a blade that I recently obtained, and noticed that the yasurime on the omote slope sharply downward and forward towards the ha ( ? ) , while the yasurime on the ura slope down and back. Both are in sujikai style, and I was wondering if there was a reason they are done opposite. Could it be that the swordsmith just turned the sword over as he held it in his left hand and filed in the same direction with his right, or is there another reason that a novice does not understand? Any education is always appreciated, Regards Scott

[Darcy]

This may help:

 

http://www.ncjsc.org/yasurime-1.html