possibly the ovum struthionis in the Montefeltro altarpiece of Piero della Francesca, identified as such by Millard Meiss - from an earlier posting
Come to think of it, the ovum struthionis leads ineluctably to the ostrich theme, and ostrich-like behavior, and so might be a suitable emblem to be used, in reminding and monitory mockery, of much of the Western world, including the Western museum-and-gallery going, painting-and-sculpting, collection-developing, connoisseur-and-tyro art-loving or pretend-art-loving Western world.
The ovum struthionis...the perfect symbol to mock those who...well, none so blind as those who will not see.
In hoc signo....
An ostrich egg, apposite for ostrich-like behavior.
The essay by Millard Meiss on the ovum struthionis of Piero can be found by googling, unless it turns out to be accessible only through one of those subscription-only services.
Panofsky, Rosenberg, Friedlaender, Gombrich, Kitzinger, and a thousand others who helped raise the level of art history in England and, especially, America -- what would happen to them, what would happen to the art of Europe, if Tariq Ramadan were to get his wish?
The Czechs put in place the Benes Decree for a threat that at the time hardly existed, and only in order not to have to further worry about the loyalties and behavior of ethnic Germans in the Sudetenland, given the record of the previous ten years. We have 1350 years of history to tell us how Muslims treat non-Muslims, and the unambiguous texts of Islam: Qur'an, Hadith, and Sira. Why should we feel abashed about discussing this? Why should it not be discussed everywhere, openly, unapologetically?