Blinking Red Lock Light

I had a blinking red light - looked like a lock - in the lower right corner of the panel when the car was parked and locked. I could figure no way to shut it off. I have not seen it before. I've had the vehicle for nearly 7 years. After a couple days it stopped. Is this something to concern me?

I read some things suggesting it should be happening every time I lock the door (sign the car is locked) and others saying no idea what it is. I don't see it in the manual.

 

What does that mean? And is the fact that it went away a good sign?
I'm going to be going back to the dealer over the tire sensor light they failed to notice. I need to know because they are likely to tell me lies.

 

So, I'm thinking another little error in a light... The car was off, locked and no key anywhere near. Since I assumed it was something about the lock I tried to open the door with no luck.
If they tell me my warning system has some glitches maybe I should listen?

 

I understand. I don't think it has been blinking before because I have seen that in other people's cars, wondered why I didn't have it. I didn't look under immobilizer though. It is definitely not blinking now. It makes an annoying noise if I leave the fob in the car so I know that is not an issue. I've had several blinking light issues, on when they shouldn't be, off when they shouldn't be. I will be going to the dealer but the local dealers are noted for finding "issues" you don't have (and being an older woman I seem to be a target) and it seems to worse lately when they have fewer vehicles to sell. I try to get as much information from the people here as I can before I go.