So why Magdalene's Egg?
First, because in the eyes of the tradition, there is something sexual about Mary Magdalene. She is identified in the Gospels only as a recovering sinner (which is a fair description of any Christian). But in non-Biblical writings, her specific sin -- the "devils" that Jesus drove out of her -- is treated as sexual. The Church Fathers (who took a pretty grim view of sexual desire) identified her as, in essence, the village tramp of Magdala. In "Jesus Christ Superstar," she is the Lord's sorta-girlfriend. And thanks to Dan Brown, half the planet now seems to think she was his wife, but it all got covered up by the clergy. (Oy, vey -- like people who can barely organize a decent youth outing to Great Adventure are soooo good at orchestrating thousand-year coverups.)
Second, because there is something religious about her. Okay, a lot religious: She is second only to the Virgin in importance among the women who folowed Jesus. Sts. Luke and John make her the first person to proclaim the Resurrection -- in effect, the first Christian preacher. Afterward -- again, according to tradition, and certainly not the Bible -- she is said to have been a missionary in either Europe or Turkey (depending, I suppose, on which cathedral's relics you were trying to promote). Scholars of the Elaine Pagels school even think she might have been the leader of one wing in early Christianity, a sort of counter-Peter.
And third, because there is something political about her. The story goes that, in the course of her mission work, she found herself at a feast held by Caesar Tiberius. You know, the guy in charge of the Whole Known World. When he runs into her, she happens to be holding an egg. She starts talking about the Resurrection, and he laughs. There is less chance, says Caesar, of that egg in her hand turning red than there is of a man rising from the dead. And withing moments, the egg turns red.
So there's Mary Magdalene and her egg, in the picture I stole from an Episcopal parish website (which I am guessing stole it from an Orthodox one). She's a symbol of things that matter: sex, religion, and politics. The world wants to keep them separate, but the Magdalene's egg stands over against the world. Desire, faith and power come together in her story -- and together, they start to tell the truth about being human.