I think the more interesting discussion is this:
If you were a North Korean and legitimately had the choice between voting "yes" or "no," how would you vote? It seems like citizens do have a choice on their ballot... it's just reported that they all voted yes.
Would you have the balls to vote "no?" I probably wouldn't.
You need to go to a "separate booth" (without secrecy) and manually cross out the name of the official candidate in order to vote 'no'. I suppose the 'separate booth' is a cheap euphemism for 'one-way bus trip to the local gulag'.