It would be infringement of the rules?

[Crazy (Crazy Psychiatrist®)]

I wonder if can do this, this new member, copied the theme created by me, just made some changes, such as inserting a logo, etc …

https://addons.mozilla.org/pt-br/firefox/addon/hummingbird-v18-by-cp/ - Original

https://addons.mozilla.org/pt-br/firefox/user/Akazie/ - (03) copies

[desktopd (Desktopd Mozilla Product Lead)]

Since the theme is without copyright licenses (i.e. all rights reserved) the published copy infringes your copyright if the original is yours.