There are a few purposes:
I thought it looked cool!
For tension wrenching in confined spaces (very hard to get tension right)
Heres a purpose more relevant to you Cityspider- you could attach an elastic band to either give you hands off tension or to use as a plug spinner.
Its easyier to hold (for me anyway)
And finally, once i have picked a lock, this end is VERY useful for turning the plug to the unlock position.
I hope this will inspire you to have this shape!
