@yogthos yes. Here's the whole explanation
https://blog.mozilla.org/firefox/the-fox-is-still-in-the-firefox-logo/
And then they created a special version of the logo for firefox nightly :)
https://hacks.mozilla.org/2021/02/heres-whats-happening-with-the-firefox-nightly-logo/
@yogthos have you seen the explanation? The 6th logo actually represents the family of products: the browser, lockwise (password manager), the vpn as well (i guess