Why docker creates `html` directory implicitly?

General
1

I mount the following volume in docker compose:

volumes:
    - ../myappname:/var/www/myappname

However, after everything is built and running, I get two directories in /var/www instead of one (myappname), with html directory being created implicitly.

docker@fe92aba21c92:/var/www$ ls -1
html
myappname