Behind his head are the two Greek letters chi and rho and that tells me at once who he is, because they're the first two letters of the word Christos, and this is in fact Christ.

在他头部后方有个希腊字母chi和rho, 这让们立刻了解了这名身份：这是希腊文christes首字母，而们所看到正是耶稣最早图像之一。