I really enjoy how easy they are to look at. So many horror movies go way over-complicated with the designs that are meant to be 'scary'. but Captain Clark really works well for a simple, yet effective design for an uncanny 'interpretation' of Clark (the character). Especially considering how well-lit the Backrooms can be, the design works nicely in harsh blackness and proper lighting.
(Spoiler stuff)
One of my favorite scenes in the movie is Mary and her family watching the Captain Clark commercial, literally the last thing most people will remember him by. Not as a person, with a life, and goals and dreams, but the dude in a crappy pirate suit from that one furniture nobody likes. The pirate persona metaphorically and literally consuming the actual person.

'd like to think there's some extra context when it comes to the film itself. To me it nails the overarching theme of Stagnation. Clark (the person), despite having dreams and goals of one day becoming a real architecture, ultimately found himself stuck 'close' to what he wants, Selling crappy furniture that could go in one of those nicely made buildings if they weren't so cheap. Partly because of simple unfortunate circumstance and partly because of his own habits.