In film theory, "mise en scene" translates roughly from French to English as "scene arrangement".
That is the ability to design and arrange a frame (props, lighting, characters, etc) to create meaning.
On basic level, a framed image can demonstrate time, place, etc.
On a deeper level, it can also create mood and convey subtextual meanings of characters or plot.
Here are two example from Citizen Kane:
Scene 1:

This frame is from the first scene in Citizen Kane -- It already tells quite a lot about the story i.e. a large, far-away mansion -- it looks very uninviting and even has signs (seen previously) upon its gate that say "KEEP OUT".
This sets up the story in part for the next scene, which is Kane on his deathbed -- We begin to wonder, "Who was that man who owned such a large house? Why does it look so uninviting?"
In other words, this scene becomes a reflection on Kane -- His house demonstrates how he shut himself off from the rest of the world.
Scene 2:

Notice how the smallest figure (Kane) seems to look the most powerful in this scene -- We get a clear sense of relationships in this scene i.e. Kane is the boss.
Such arrangement of scenes is particularly used in film noir, which bring me to adventure games.
Grim Fandango -- very film noirish game.
Certain framed scenes tell a lot about characters and story.
For example:

We learn a lot about Manny in this scene, such as the impression of the messy pile of books on his desk, and the dark decor and lighting.
I'm sure there are tons of other scenes from countless other adventure games, which is what this GTD is about.
Discuss your ideas on background construction and it's relevance to creating meaning in the game.
Think about questions like these:
* What does the foreground tell you? What about the background? How do both contrast?
* How is the scene lit? What kind of atmosphere does it give? How does this contribute to the game?
* What about certain motifs (reoccuring patterns or symbols)? i.e. the closets in Pleurghburg (as a symbol of Jake's fear)
* Does the frame offer some odd camera perspective? How does think create meaning?
* How does the background, characters and objects work together in a room?
These are just basic questions to get you started, but I'm sure people can expand upon this topic.
Here's an good article to give you some ideas too:
http://members.tripod.com/~aarrrggghhh/misnscn.htmlCheers!