Sean O'Kane is the photographer for the photo.
You can choose from three driving profiles that will dictate how the car will react to certain situations on the road. The aggressiveness of each mode varies.
The feature was included in the October 2021, version 10.3 update, which was pulled two days after it started rolling out due to an issue with left turns at traffic lights. The release notes for version 10.3.1 show that the profiles still exist, as shown on the Not aTesla App. According to the notes, the way to control behaviors like rolling stops, speed-based lane changes, and yellow light headway is through the use of FSD profiles.
An image posted to the social networking site gives us a better idea of what this actually means. The vehicle will have a smaller follow distance and perform more frequent speed lane changes according to the description beneath the assertive option. It is not clear whether cars will come to a full stop at stop signs if the vehicle is not exit passing lanes.
A video on the internet shows all three modes in action, and at the end it shows howTesla describes each profile. The vehicle will have a larger follow distance and perform fewer speed lane changes in "Chill" mode, while "Average" mode means the car will have a medium follow distance and may perform rolling stops. It is difficult to tell the difference between these modes from the video alone, as it does not test out the vehicle in heavy traffic or harsh weather.
It is difficult to tell how much these profiles change the way the vehicle drives, and if they push the limits of safety when traveling in the rain or snow. If the descriptions of these profiles are accurate, this means that a car in assertive mode may follow cars more closely, come to rolling stops, and swap lanes more frequently.
It is important to point out that the car isn't completely self-sufficient, but a "feature complete" version would allow users to drive to and from work without intervention. The National Transportation Safety Board warned against the use of the Safety Score system in the FSD, which was rolled out to more users last September. The first crash of its kind happened in November, and it appears to be the first crash of its kind.