You're welcome, and you're correct in thinking the upvote reward would be reduced accordingly in the instance you described. Your voting power will always fluctuate in response to what others are doing, it doesn't really define a set dollar or Steem reward. Rather it is your influence in voting where the reward pool is distributed. 

Since the reward pool is fixed and finite, we're only steering the rewards, not creating them. In your example the whales would definitely see the dollars their votes were giving decreasing as more votes were cast by other whales.

Imagining an extreme scenario to the other side... if by some strange circumstance nobody on Steemit voted on a given day except for you... your vote would direct $100k plus of rewards simply because everyone else essentially abstained!

One real world scenario that people often can see but not understand is how their post may actually decrease in payout value as it approaches the full week, even with the price of Steem stable. This can happen because most of the time the votes we receive come in early on in the week and then die off. If later in the week a bunch of whales get more active, some big news happens that results in a few posts raking in major payouts, etc. your payout can decrease as the active voting shifts some of the reward pool another way. It's a never ending tug of war contest and the rope can move back and forth all the time!