The fourth known incarnation of the Doctor, who was played by Tom Baker, was noted for wearing a very long scarf with various shades of red, brown, green, and purple (see below). Laura Ducros crocheted this ankle-length dress in imitation of it. She's also wearing a very thin version of the Doctor's scarf around her neck and his hat.
Bonus item: here's Ducros posing in her dress with Sylvester McCoy, the actor who played the Seventh Doctor.