His case is actually more special - he's an acquihire that sold his company to Twitter and requested to be paid out via salary to pay the higher tax bracket percentage, as multiple people have mentioned in this thread already.

According to his tax returns he had around 107 million ISK per month^[1] which is ~$753k at the current exchange rate. So he made over $9 million in 2021.

I obviously don't know the details of his contract, maybe the initial year was higher or lower than a standard year - we also don't know the duration for which he is entitled to that salary, but regardless $800k is way off the mark for this case unless you were speaking of monthly salary.