McCloud rather eerily anticipates the advent of momentum scrolling and it’s effect on screen-based temporality in a sequence of Reinventing Comics. Here, he conducts a thought experiment involving two figures, A and B, each containing a pair of squares. The first figure, he tells us, depicts two squares sitting side by side, while the second figure, visually identical to the first, depicts the same square at two different moments in time. “Run your finger over A,” McCloud explains, “and that finger is moving through space. Run it over B and it’s moving through time”.
When McCloud talks about our fingers moving through time, he’s talking about something called diegetic time; the time in which the story unfolds, as described in the temporal map of comics. But in the age of the touchscreen interface, it's inescapable that we’re also talking about non-diegetic time, or real-time—the time of the user’s interaction. We are playing in both worlds simultaneously.