The meaning is a little bit different. It is very difficult to understand the meaning of this passage without context. This passage is talking about how in Christian paintings during the medieval period, there would be pictures of Jesus holding scripture. “embodying the text within itself” is talking about how by creating a visual link between Jesus and the scripture, the text becomes Jesus speaking to the person. The “classical and pagan way of seeing texts” is the way we think of books now. If I write something, there is no voice. You do not know what I sound like; you do not know who I am. This is not how you are supposed to see scripture. A person was supposed to think of scripture as if Jesus was speaking it to them. Thus it is given a voice it would not otherwise have. I hope this helps :P. If you have any questions let me know.