The mod doesn't shows all the portraits under the Linux version. I tracked the issue that the file names and the paths in the configuration files of the mod don't match. Linux is case sensitive, it consider upper case and lower case as two different characters, while Windows is case insensitive. Under linux the game doesn't see the files despite there is the entry in the game files, because some letters are upper case while the name file aren't.
I'm able to fix the issue by my own renaming the files, but I would ask you kindly if you can update the mod with the filenames fixed for Linux users. All what you have to do is change the filenames and make them match perfectly with the entry in the config files.