Well, I think the plus side to have the entries anon would be because it eliminates and bias so the work would be judged on purely for its artistic qualities. I think that normally the name of the maker who makes the siggies also comes into account when casting votes so danger here is that it may end up being less "a judge of art" and more a popularity contest. So having the siggies anon would ensure a fair vote.
But the styles of the makers are a big give away to the identity of the maker (not so much for me as my style varies pretty much all the time
), but for someone like Riker, its a pretty easy guess.