eisai_xaso provided the link to these pictures, but I think I know who the "unkown actress" seen in the seconde picture further down the post is. Is it just me of is that Gabriella Bussoni, the woman Jack kissed the night Sarah left him?
The artikel presents the pin theory as a part of an effort to provide explanations on the season 5 spoilers. This is also available in Lost-theories.com