This role is in the brand management team with responsibility for the Doctor Who brand specifically. The Commercial Director is responsible for directing all commercial aspects of the brand, running its P&L, representing the brand internally and externally, and managing and protecting the brand in general.
In addition to approving products and communications relating to the brand, you'll also identify and develop new business opportunities, including creating and executing a five year plan for the brand.
The role specifically refers to a "five year plan", which is good news for Doctor Who from a commercial perspective, though this does not indicate a further five years of the show itself, of course!