In addition to a playable Sonic the Hedgehog game and TikTok, Tesla included UI changes.
"The most useful inclusion in the update could be its blind spot camera feature which automatically shows a live camera view of the car’s blind spot whenever a driver activates a turn signal. Tesla CEO Elon Musk indicated the feature was in development in July 2020, but now it’s here to (hopefully) make maneuvers like changing highway lanes a little bit safer.
Other practical improvements include an easier way to add multiple waypoints to a journey, and simplified controls for accessing a car’s primary controls. It’s also now possible to drag and drop your most frequently used apps to customize the car’s menu bar, and the heaters in the front seats can now regulate temperature based on how hot it is in the car generally."
www.theverge.com
"The most useful inclusion in the update could be its blind spot camera feature which automatically shows a live camera view of the car’s blind spot whenever a driver activates a turn signal. Tesla CEO Elon Musk indicated the feature was in development in July 2020, but now it’s here to (hopefully) make maneuvers like changing highway lanes a little bit safer.
Other practical improvements include an easier way to add multiple waypoints to a journey, and simplified controls for accessing a car’s primary controls. It’s also now possible to drag and drop your most frequently used apps to customize the car’s menu bar, and the heaters in the front seats can now regulate temperature based on how hot it is in the car generally."

Tesla’s big holiday update adds TikTok and playable Sonic the Hedgehog
Blind spot cameras can now turn on automatically.