There is actually more to it than that. The numbers are only an ESTIMATE of what will be paid. When the final day comes everything is then re-calculated and the pie (the reward pool) is cut up and distributed based on the final calculation, not the estimate. I wouldn't pay too much attention to those estimates except to know very roughly what can be expected. In the end, your curation rewards are always split between SBD and Steem, so you get half to each.