Directors are more like hired guns in TV. They come in and match the show's established style. It's only in the rarest of cases, for some prestige TV shows, that a director is allowed to insert their style into an episode. But generally, you have to match the style already established. The Showrunner (executive producer/writer) is the actual creative driver behind a TV show.

Few TV shows have outspoken signature styles. It's much easier to mimic.