In the Blackfriars Crown Court case, the Judge could have cut through the human rights stalemate. He could have said something like this to the defendant:
“As long as some one can identify you as the person who has been charged, it is your choice if you come into Court with your face covered. It will not affect the way that I treat you, which will be exactly the same as any defendant. However, you should perhaps reflect on what the jury will think. If they cannot see your face, they will not see how you are reacting when the prosecution evidence is being given, and if you choose to give evidence they will not see the manner in which you are answering questions. They may well want to take account of body language and facial expressions, as people do both in and outside Court. I will direct them that they must assess your evidence in the same fair manner as they would any witness, but you may find that because they cannot see you, they will give your evidence less weight. These are things that may harm your defence. If that is a risk you are prepared to take, it is entirely a matter for you”.
So the defendant is treated as a mature person capable of identifying her best interests and she can make an informed choice. If the veil is so important to her that she’s prepared to risk the jury taking against her for it, on her head be it.