Subjective time, as opposed to clock time, is fundamental to our experience of film or video and, by extension, TV advertising. The elements of a commercial may be the pictures and the words that you can lay out on a story-board, but the audience experiences a commercial as movement, ideas and images that arrive in unfolding sequences that surprise, involve and persuade. The intuitive decision-making that shapes the tempo of audience experience is the creative art of editing.
Someone once described editing a film as the simple process of cutting out the boring bits. There is more to it than that, as can be seen in the range of film structures created over the years. Narrative rearranges time, with cuts, camera movement, close-ups, flashbacks and flash-forwards, to manipulate audience attention, memory and anticipation in the service of dramatic storytelling. Montage destroys time, juxtaposing and fusing images to create new insights into the deep connectivity of reality.