A MacGuffin is a plot device that motivates the story's characters, but whose specific nature is unimportant to the overall plot.

But is there a term for a plot device that is a primary motivator for the audience, but that the characters are not invested in, or are even oblivious to?

For example, at the beginning of Fear The Walking Dead, the audience knows what is going on, but the characters are otherwise occupied. In fact, the primary attraction is that, we know what is going to happen, and we want to see how the characters will deal with the unfolding realization of it.

Is there a term for this?