I wrote this text to accompany the drawing when I put it on DeviantArt:
The slave hung from her wrists, her back pressed against the end of the fearsome sedile. The position stretched her ribcage, making it hard to exhale, and forcing her to take shallow, fluttering breaths. Soon she would have to push herself up with her legs, forcing down against the nails through her feet, and pull with her arms, just to be able to breathe, otherwise she would asphyxiate. But the agony would be excruciating, and besides, she had not the strength to remain like that, so she would soon sink down again.
Of course, she could always come down on the sedile, taking the strain off her arms and ribs, allowing her to breathe easily, without inflicting tearing agony on her wrists and feet. But... she looked over her shoulder at the phallic protrusions reaching up towards her... that would mean impaling herself. She would have to choose between impalement and asphyxiation. She already knew that everyone chose impalement. There was no choice, really. The only question was when.