In some cases. But this little display is about superiority.

[She looks over at the poor prisoner, nursing his wound, as the next is dragged up to the display and seared. The smell of burning flesh fills the air, and her nose wrinkles.]

It's meant to remind anyone not in this country that Olympia is the superior country. They'll release the prisoners soon, I'd imagine, just so they can wander back home and spread the message.