Why does Ruth Bader Ginsburg wear a bib?

[Binyamin Yisrael]

I was looking for a picture but I couldn't find one I could post. Then I typed Why does... and it suggested the title of this thread. So my question is "Why does she wear such a stupid costume?". None of the others do it but I did see one with another female justice do it. What is this?

[Havok]

http://en.wikipedia.org/wiki/Jabot_(neckwear)