Docker start options

Hi, I am kind of new to Docker but have quite a lot of containers running nonetheless and love it!

There is something I can't get my head around though, and I hope someone can explain this.
When I run a container from an image, and set a lot of start options/environment variables, these are visible in the details of the running container. My question is, where are these saved? Are they saved to a Dockerfile somewhere?
When Watchtower starts to update images and re-create containers, it knows what run options and environment variables to set, so it must get them from somewhere, right?

Let me clarify: The options I am using to start a container with (see screenshot) are saved in appdata outside Docker?
Where would I be able to find them on a Debian OMV install? Can you give me an example of such a config file on the file system?

I'm starting to think the start options and environment variables are kicked off in the Docker run command when the container is started and are not actually stored anywhere, could that be true?
Stil doesn't explain how Watchtower knows about all of them though...