Sometimes there's some famous name deep in the backstory of your campaign world that the players might have vaguely heard about. For example, in a conventional Dungeons & Dragons game, there are names like Mordenkainen and Elminster that players could easily know by reputation.
When they're doing something completely random, maybe they uncover some ancient bit of lore. The magic sword they are seeking was enchanted by Elminster. Or the ancient castle they are exploring was once the home of Mordenkainen. Just dropping the names casually into the adventure can cause excited gasps from your players. Well worth it!
(Of course, that's not happening in this strip, since none of the players have any idea who Mara Jade is.)
Commentary by memnarch (who has not seen the movie)
Mara Jade? I think I remember that name from some really old Star Wars books! Which is pretty cool to have a reference like that. But it would also mean that the parts with Rey wondering about her mother aren't in the movie as Disney likely wouldn't bother getting creation rights when they can make their own stuff up. Add in the business with the clone getting turned evil, and I'm pretty sure we can safely say that none of the plot here is close to the movie. It also neatly wraps up the absurdity of trying to have two Lukes running around outside of the Muppets setting.
But where's the fun in just saying "it's all part of the comic story"? I can tell that Luke looks like he's getting yelled at or been tossed around a bit. Maybe this is the start of the next scene following a cut from Chewie bursting through Luke's door? I could see Luke being scared or rough housed by a "walking carpet" as a thing this director could do with the odd decisions so far. Perhaps something that starts as a joke for a bit more levity after the big space fight and Team Bad Guy scene. And if Luke's a full pacifist now, that'd explain why he's not just Force Pushing Chewie and Rey away, and also why he tossed the lightsaber over his shoulder.
Oooo! Tangent back to the comic plot; since we can deal with random clones of people in the comic, how about being a clone of the shapeshifter assassin? Luke had that thing about not trusting Wedge all the time, and while he kinda got over that, Wedge still wasn't someone who Luke would have wanted to marry. Maybe something happened with Mara the clone that made Luke become a pacifist and run off to live alone on a deserted island.
GM: Uh, right. Shall we return to Ahch-To?
Rey: All right. So. My mother? Who is she? Is she still alive?
Luke: She’s dead. And a good thing it is too.
Rey: What? That’s my mother you’re talking about!
Luke: Her name was Mara Jade. I loved her. But I didn’t realise what she was.
Chewbacca: She wasn’t a Wookiee, was she?
Luke: That I would have noticed. No.
Luke: When I met her, she was second-in-command to the smuggler Talon Karrde.
Luke: Karrde helped me in a sticky situation, so I owed him a favour. Jade and I busted him free from captivity.
Luke: We ended up fighting the Dark Jedi Joruus C’Baoth, who had taken a clone backup of me that my Uncle Owen and Aunt Beru made, and turned it to evil.
Luke: Jade killed my clone and, well, it was love at first sight.
Chewbacca: If that counts as first sight then I have very dire expectations about your future love life, Corey.