Imagine if a developer decided to solve performance issues with a game.
He looks at the character model generator. The characters are rendered in clothes at the drop of a hat, it's all modular, it's amazing. Paradox is proud of this achievement.
Naturally, you'd think that only the heads, the hands and the clothes are rendered, and when you have a naked tribal or slave the rendered body is simply just under the filename of "Clothes - Naked".

But we live in a competency crisis and the body is always rendered.
To solve this, Paradox has made the body emaciated whenever clothes are rendered on top of it, so it won't clip through. Papering over the cracks.

Worse still, you're finding out about this from a screenshot that's actually a photograph from a phone because the players, unfortunately, have the same IQ as Paradox developers.