You'll get a sliding bar which appears under the upvote button after you vote. This comes with reputation and amount of steem power you hold. As your reputation and steem power grow, so does the amount that you can pledge to a person for their post or comments, that you appreciate.
I think in the fish hierarchy, I'm considered a dolphin...today when I voted for your comment at 100% of my voting power, that gave you $1.66. When the price of the SBD goes up, so does the amount of my vote. When I have a higher rep, 100% of my voting power may equal $3 per vote. Whales can pledge a lot per vote or downvote a lot, so if you asked me who runs Steemit, I would say we all do, with the addition that some have more influence than others.
Please never feel bad about the difference in upvote $. I worked hard to earn the right to give $ to whomever I want to. I remember what it is like to only make a few cents on a post. This is my way of "righting" that flaw in the system. You'll notice that I don't always vote at 100%. This is because I feel responsible to award appropriately. I upvoted your comment at 100% because it contains valuable information about how Steemit works. (Great question, by the way.)