You linked to the explanation of seasonal adjustment, but you apparently didn't understand.The non-seasonally adjusted number of workers went DOWN by 476,000 workers?!?
Table A-9. Selected employment indicators
'What is seasonal adjustment?
Seasonal adjustment is a statistical technique that attempts to measure and remove the influences of predictable seasonal patterns to reveal how employment and unemployment change from month to month.'
What is seasonal adjustment?
So, Americans made less per hour and per week AND (removing the BLS's creative math - er - 'statistical technique') almost 1/2 a million fewer Americans were employed.
Employment usually goes down in December. In the last 50 years employment has gone down 38 times in December.
So…how much of the change was the economy, and how much just December?
It's like measuring water level at the beach: you have to compensate for the tide.
Further example, not seasonally adjusted total employment has never ever gone down in June. So employment going up in June means nothing. You have to seasonally adjust or you learn nothing.