You can certainly tie this fly either way. I usually tie it with the natural feather and no shaping on my part. I believe this is the way the pattern was originally tied. The feather will skinny down in the water and will assume a naturally tapered, 'pointy' tail if you will. I wonder if the others we see are not tied using some sort of adhesive to point the tail thus simulating in a display fly the appearance of the fly when wet.
I suppose if your purpose is the later, than pointy makes sense. If it is the former however, the water will take care of shaping the fly naturally.
Tight lines,
George