Explanation: The image is from The Onion, a satirical news site, and is making fun of this kind of political cartoon.
The Romans celebrated SATVRNALIA around this time, a jolly winter holiday in which people exchanged minor gifts and snacks, celebrated together, played silly holiday games, wore outlandish clothing, and in general turned the social order 'upside-down' in the name of the liberation represented by the god Saturn, and all people were (theoretically, and by custom, not law) equal for the week, from the highest masters to the lowest slaves.
IO! SATVRNALIA!