Hassig has written a chapter on specific details of mediaeval portrayals of Jews/monsters/others/foreigners/devils, all of which elide rather tellingingly at some point. If I recall, there were several things that functioned most strongly in depicting evilother, among them distorted faces, grimaces, crouching posture, tightly curled hair and dark skin. All of these features are not only present in these unpleasant-looking lads, but accentuated by contrast in every case to the serene, upright, very pale figure between them. So they are associated, not only by narrative function but by visual language, with the actions of the devil. Standing in for him in the physical performance of Agatha’s martyrdom, they take on physical attributes associated with him – but also, of course, with themselves as ethnically other.
So Christianity’s tendency to create enemies  comes in handy here – we have a sliding scale between foreign and devil, between not-us and persecutor and enemy of God, where the only difference between foreigner, pagan, idol, demon and Satan is of degree.
As the corollary to this, what does Agatha resemble in this picture? Well, in context, that’s rather obvious – who stands around looking bright and benevolent while surrounded by tormentors, with arms stretched out to either side of his head? And is a complete contrast to devils? In case we missed the similarity, she has her convenient halo to point it out. There is also a clear sexual difference – she is pure and white and fully clothed (save where they have exposed her body for humiliation and torture) with skirts to the ground, while their legs are bared and the violating instruments are held in a suspiciously phallic position.
Physically, she is approaching (literally) Christ – she is raised above her tormentors, as if halfway to heaven. And alright, so she has breasts and that’s not entirely Christ-like – but hey, her tormentors are (sergeant-like) removing those for her, so that won’t be a problem for much longer. Remove those curves, and she would be almost entirely masculine in appearance.
Of course saints are often depicted as resembling Christ, or rather partaking of the same visual code of virtue and holiness, just as the torturers resemble the devil. But a female saint is visually farther from Christ to begin with, and it’s hardly illogical that she should become masculinised in depiction in the process of approaching him. Caviness has mentioned the tendency towards masculinisation in the tortures visited on female martyrs - Agatha’s isn’t the only mastectomy, and the torments often appear to result in a masculine display of physical courage or fortitude, etc (Caviness 90).
I’ve described it as purely visual, but of course the cultural attitudes are hardly limited to the pictorial. Though Caviness is primarily discussing images, rather than literature, she implies that this tendency is also present in the shape of the stories of the female martyrs: “The threat of the female is expunged by her becoming masculine (or female-less) in response to bodily exposure and torture. The repetition of the mastectomy topos in so many saints’ lives, possibly by a borrowing from one to the other, is an indication of its cathartic power” (93).
But doesn’t this imply that ‘female’ is something expunged from the body to leave a pure male remaining? Yet the feminine is already defined by its lack relative to the male body, so logically in lacking both masculinity and femininity one becomes genderless. Is there, then, a similar tradition (though fainter, I think) in the purification of male saints by castration? I can’t think of nearly so many instances, but one could construct an idea of an idealised non-gendered spiritual body, purged of sex.
Of course, this is rather too (theo)logical and rather less fundamentally attractive than the idea of ripping off women’s breasts or ‘improving’ the bodies of admired women until they resemble men (the best of men), so it’s not likely to have such a wide currency in popular stories.
 Cf. the faces of the people flaying St Barthlomew (from the same ms) in the picture at the end of the last post: one's turning his head away, one looks uncomfortable, and one looks like he's positively enjoying himself. All three are similarly dressed to Agatha’s tormentors, and the face of the third is the most distorted.
 Unfortunately I haven’t read this article for over a year and my photocopy of it is in Canada and I can’t source it over here in Adelaide, but I shall sharpen the specifics as soon as I get back to Ottawa. I don’t think my memory misrepresents her.
 It's ridiculous, isn't it? given the cultural dominance of Christianity for, oh, 1700 years, its insistence on a neurotic self-representation as a persecuted minority. Childhood really is a very formative time, apparently for religions as well as people. It is a very attractive self-representation too, isn't it - it means you needn't mature emotionally beyond that childhood phase of ranting at injustice and being misunderstood, and may construct enemies everywhere at a moment's notice. After all, you're the victim, right?
 This raises a question, which I’m not addressing now because I’m really just thinking aloud (well, on a screen): Are any female martyrs depicted in a Marian code, rather than a Messianic one? I can’t think of any, and it’s less intuitive – but are the unmartyred female saints depicted consistently in the visual tradition of Mary, then? Is there an appreciable divide there?
Caviness, Madeline H. Visualizing women in the Middle Ages: Sight, spectacle and scopic economy. Philadelphia: U. of Pennsylvania P., 2001.
Hassig, Debra. "The iconography of Rejection: Jews and other Monstrous Races". Image and Belief: Studies in the Celebration of the Eightieth Anniversary of the Index of Christian Art. Ed. Colum Hourihane. Princeton: Princeton University Press 1999. 25-46.