As some of his characters for “The Prisoner” were already shown in two promos for the episode, Bryan Arnett published the corresponding designs—the above image—on his freshly started Tumblr account. Follow away!
After the episode, he typically publishes a more complete set of these, so bookmark this article and check back when the episode has officially aired. You can find his designs for the previous episodes on the production tag.
So he did; see Bryan Arnett’s Tumblr or the gallery below.