the 542 sats including the rewards, the wallet stats of that post only showing the sats stacked from stackers.
so I guess your post stacked around 84 sats, sn take 1%, 75.6 left; but you have earned some rewards for the pool, so everything added up is 542 sats:)
PS: there should be somewhere mentioning in your wallet history
SN distributes the sats it earns back to its best stackers daily. These sats come from jobs, boosts, posting fees, and donations.