If you could not tell...there on that platter Saint Agatha of Sicily holds her severed breasts. Just like most ancient anecdotes there are multiple versions of Saint Agatha's story. Saint Agatha is one of the most highly-venerated virgin martyrs of the Catholic Church. She notably fully dedicated her life to God. She had a very flattering appearance, and decided to remain celibate and devote her life entirely to Jesus and the Church in a life of prayer and service. Though she had made such a decision that did not stop men from wanting and desiring her. 

One in particular was Quintianus. He was a very well respected male of high diplomatic ranking, and he thought he could force Saint Agatha to go against her vow to God. Upon many rejections he decided to have her arrested and tried before a judge. The judge was no other than Quintianus himself. He anticipated her giving in to his demands when he explained she would be tortured and and be faced with possible death. Instead she reassured her faith in God praying for courage and strength. To once again attempt to change her mind, the determinated Quintianus imprisoned her in a brothel. Through such undeserved conditions she still never lost faith. She was interrogated and during her interrogation she told him that to be a servant of Jesus Christ was her true freedom. In retaliation of her undesireable reactions, the infuriated Quintianus sent Saint Agatha to prison instead of the brothel hoping to instill more fear in her - though it possibly brought a bit of relief. 

Bothered by her joy Quintianus ordered that Saint Agatha be tortured and in some versions as he noticed her endure these different forms of torture, such as being whipped or burned with torches, with a sense of cheer. He ordered that her breasts be cut off. In other versions she cut them off herself. Since Saint Agatha is the patron for breast cancer patients,  rape victims, and wet nurses, I'm pretty sure all would agree that it would make the most sense for her to have severed her own breast simply showing her own power and agency as a women and also it's simpluy more badass, but we as receivers and readers are not the ones who make the story, we are just the ones who may tell it.