Before knowing the answer of this question you have to know from where the reward is actually coming from. Witnesses of steem blockchain produces blocks. Every block contains a amount of steem from where the witness get 10%(only that witness who signed the block), 15% get divided to all stake holders and the rest 75% goes to reward pool. The reward we generally get, comes from this reward pool.

There are 3 option of posting- 100% power up, 50%sp/50%liquid and decline payout. When a user post on `decline playout` option, that means the user don't want to get reward from the pool. The reward will not come to the author after 7 days but will remain on steem reward pool.