Santa is fat at the start of his trek. One year of inactivity and the plentyful and good food Mrs Claus makes sure of that.
After stressing around and climbing chimneys for one whole day, without rest, he is both mentally and physically finished.
The complaining Rudolf and pack did not help his mood either!
Gary caught him the moment Santa has left the absolutely last package, thrown towards the front door DHL style.
Tired, disappointed, starving.
(
. My take on the scenario behind the excellently carved and coloured piece! )