Nothing really, it is just part of the forum software we use called Xenforo. Currently the trophy points are just used to show how active a member is. Also the title under your username (if you are a free player) is based on trophy points: 0 - New Member 5 - Member 25 - Active Member 45 - Well-Known Member
I know this will never be used, but we should have it so that you get 1oo rupees for every trophy point that you have. Just a thought though.
Yeah I like the idea of rewarding with rupees, the problem is that it would encourage people to spam forums for points