The ghost at the funeral

I know this must have been brought up before, so sorry, but...what's with the face that appears in Michael's coat at the Don's funeral? It's when Tessio asks Mike for a word, and as Mike gets up his coat about fills the screen and a woman's face appears. As I said- there's no way this hasn't been brought up before, I just don't know where to look.
Thanks!

I've wondered that as well. I always figured there was a piece of glass in front of the camera as some sort of filter/tint and when Michael got up the lighting was shifted and someone's reflection on the glass showed up. Now that's a complete guess of mine, so someone else's knowledge would be nice!

http://www.gangsterbb.net/threads/ubbthreads.php?ubb=showflat&Number=511874&page=1

And photos here...

http://www.thegodfathertrilogy.com/ghostly_image.html