McBluffin

In screenwriting, the term "MacGuffin" is used to describe a particularly ingenious plot device, developed in part by Alfred Hitchcock. It refers to an item of great significance to a story. It moves the plot and motivates all of its characters, but what exactly the item is, is so inconsequential that it need not even be revealed. Like the unseen, glowing contents of that briefcase in Pulp Fiction, the mystery is far more interesting than any tedious explanation ever could be.
In "M Night Shaymalan's the Happening", director M Night Shaymalan, the modern day Hitchcock, has created a new device that is essentially the opposite of a MacGuffin. We'll call it the "McMuffin". The McMuffin is an Item, here a moodring, that is described, explained, and discussed many, many times throughout the film, tantalizing the audience's curiosity as to how it will figure into the storyline and why so much screentime is being devoted to it.

Can the moodring somehow be used to detect the "emotional aura "of the disgruntled plants surrounding our heroes? Will the nature of its chemical reactions inspire a way to stop the poison tree gas from being released in the first place? Will its color betray that a character has been stricken emotionless by the airborne toxin and is seconds away from going all suicidey? The twist (Shaymalan's speciality) is: that it has nothing to do with the plot whatsoever, nor does it offer any symbolic insight of any kind. It existed only for the characters in the film to make small talk about, and also to generally waste our time. The director knew that audiences are generally distracted by shiny objects, and that they might not spend those scenes fixated on the awkward dialogue or improbable events. Well played Shyamlan. McMuffin!