Docker filesystem layers can be tricky to wrap your head around, and even more so how indoes work. Lets take an example and see what happens when you tail a file that exists in the image as part of your container entrypoint:
host$ docker run -d --rm --name test-inode debian tail -f /etc/issue
54bbfa8fa1f6751593dcf23103a1cdaec7fde8ffbcb3e31bab466b4f7a3581e7
Now make some changes to the file: