Poll: Who IS that?

SPOILER WARNING! Photo and comments posted here may contain spoilers.

I’ve noticed one hot topic of conversation about the ‘Dinner Party’ photos, and thought it deserved a poll of its own.

The Office Dinner Party

There seems to be a lot of speculation over who this woman is, pictured on the left. I’ve collected all Tallyhead suggestions into this poll:
P.S. Do I know the answer? — absolutely I do. :)