Dog Mode is just what it sounds like: a feature designed to keep the cabin of your car at a comfortable temperature.
Not only that, but it’ll display the temperature in the car on the touchscreen so that passersby will know the pup is safe and sound. Here’s a more detailed description from Tesla:
Keep your dog comfortable in your car while letting people passing by know they don’t need to worry with Dog Mode. In addition to keeping the climate control on, the touchscreen will display the current cabin temperature. To enable Dog Mode, tap the fan icon at the bottom of the touchscreen when your car is parked. Set Keep Climate On to DOG, make adjustments within temperature limits, then leave knowing your pet will stay comfortable. Dog Mode will stay on after you leave your car. If you your battery reaches less than 20% charge, you will receive a notification on your mobile app.