From your picture your wine looks carbonated. The "tang" may be partially coming from that, also, I've noticed a younger wine seems to have a twang to it until it ages properly. How old is the wine in the picture?
If you let us know the ingredients you used to make your wine it will be easier for people to comment on your "tanginess". (ie. did you add extra sugar to up the starting SG?)
If you let us know the ingredients you used to make your wine it will be easier for people to comment on your "tanginess". (ie. did you add extra sugar to up the starting SG?)