The vehicle is a 2017 Honda Accord Hybrid, purchased new in California.
Last night, after locking the vehicle in the driveway, a slowly-blinking red LED appeared on the instrument panel. The light is just above the left turn indicator light, and can be seen on this screenshot from the car's Owner's Manual:
The illustration shows the light, but I cannot find in the manual any mention or discussion in the text of the light's function.
When I'm sitting in the vehicle with the remote key in my pocket, the light stays off. I opened and firmly reclosed all doors, the trunk, and the hood to make sure they were securely closed. They were. When I manually lock the vehicle using the remote fob, the light begins blinking again. No other error messages or lights are illuminated, and the car starts and drives correctly.
What does the light indicate?