Fans are set to put forth many theories about what is going to happen in Star Wars: The Last Jedi and Mark Hamill is going to mess with these fans. One of the recent theories that has been proposed is that Luke Skywalker will go bad in the new movie. This theory is based on the fact that a new North American poster puts Luke at the top and behind other characters, a position held by the villain in previous Star Wars posters. Hamill is messing with the theory by presenting a Last Jedi poster for another region, that seems to have a different villain.
A similar poster that has been released in Asia does not put Luke Skywalker in the “bad guy” position, but, Rey. Mark Hamill had sent this poster out on Twitter with a great conspiracy theory hashtag, likening the “Luke is evil” theory.
The “Rey is evil” theory has some support. The most recent trailer for Star Wars: The Last Jedi, is designed in a way to make fans think that Rey may turn to the Dark Side. While it is possible that this is intentional misdirection the idea combined with the poster will feel like they were designed to reinforce this idea, assuming one believes the bad guy is always at the top of the poster.
It is true that there are many posters for the episodes in the Star Wars saga that include Darth Vader or the Emperor in that top position. Lucasfilm has been keeping spoilers so close, it is unlikely that those who had designed the poster knows if Luke or Rey will turn to the Dark Side.
China has never had the connection to Star Wars that those in the west have had. This means that making Luke Skywalker a major face on the poster would not make sense. Anybody in China who looks forward to the follow up to Star Wars: The Force Awakens is interested in Rey, so she is given the focus on this poster. It is marketing, not a spoiler.