That's a good question - I've always just clicked the button.
I didn't really get why the button needed to be there - and the rewards weren't just paid out automatically; I look forward to finding out the answer to your question.
Congratulations on your first payout / rewards for blogging on Steemit.com ^_^
Thank you sir, I'm sorry searching for answers, once I do, I'll share with you, meanwhile I want to add you to my steemvoter.