From the title ^ I loaded up my game today, and the portrait from that pack was replaced by the default portrait from the game. It’s fine if so–I will just set up another portrait. I just wanted to check.
But yes, to explain the game behavior, I was silly and had installed it from steam. I have to remind myself to not do that again.
At this stage, I am tempted to explain it through the current trends of Nexus preventing removal of mods. Maybe the mod author doesn’t want their work to be included in compilations that can’t be taken down.