McQuarrie's imagining of a "laser sword" battle between Darth Vader and a character who was initially named "Deak Starkiller." The character would eventually be renamed "Luke Skywalker" in a later draft. Both characters wear breathing apparatus, like they might if they were jumping from ship-to-ship in space. The background is a ship hallway design that was later used as the hallway on Leia's blockade runner in the first movie.
https://files.mastodon.social/media_attachments/files/110/537/569/319/042/483/original/93bd6d10589ae13c.jpeg