People watch television while answering messages, scrolling, shopping, working and investigating whether the actor playing the pathologist really was in Downton Abbey. Sometimes television has become extremely expensive radio with pictures. This presents writers with a problem. If somebody looks away at precisely the moment we discover Nigel murdered the dentist, twenty minutes later they may have absolutely no idea why Nigel is being chased through Croydon. So the screenplay helps them. "Ever since we discovered Nigel murdered the dentist…" Excellent. We're all caught up. Except some of us were watching. We saw Nigel murder the dentist. We saw the police discover that Nigel murdered the dentist. We then watched Nigel confess to murdering the dentist. At this point, we are reasonably comfortable with the concept of Nigel and the dentist.

There is a perfectly rational commercial argument for repetition. Miss an important piece of information and you may lose the plot; lose the plot and it becomes very easy to press BACK and open TikTok. But there is a nasty circular logic here. If we assume viewers are distracted, we repeat information. If we repeat information, viewers discover they don't need to pay attention. So they become more distracted. Congratulations. We have designed television that trains its audience not to watch television. Meanwhile, the attentive viewer gets punished for doing exactly what the writer asked. They watched the scene, noticed the clue, remembered the name and understood the subtext. Their reward is the scene again, this time with somebody explaining it.

AI makes this particularly interesting because it already has a tendency to repeat important information. Tell it that something matters and it can become rather anxious that everyone has forgotten. A character explains her childhood trauma. Then she alludes to it. Somebody else discusses it. Then she explains it again. Combine technology that likes repeating itself with an industry worried about viewers who weren't listening the first time and we have a potentially dreadful creative alliance. The result may be perfectly comprehensible television that nobody actually needs to watch.

Good storytelling repeats things constantly. Motifs recur. Ideas echo. An object changes meaning. A line spoken lovingly in episode one returns as a threat in episode six. That is payoff, not redundancy. The test is brutally simple: has the meaning changed? If information returns with a different dramatic consequence, it is doing work. If the audience is receiving essentially the same information in essentially the same way, you are probably just saying it again.

There is another kind of second-screen viewer who complicates the argument: the person watching something they've already seen six times. They put on a favourite series while cooking, playing a game or recovering from a day requiring rather too much use of their brain. They know the characters. They know the plot. They can hear a scene from across the room and know exactly where they are. Then something happens. The phone goes down. A favourite exchange. A beautifully played scene. A joke they know is coming and still find funny. Something that still makes them cry despite the minor inconvenience of knowing perfectly well what happens next. That may be one of the harshest tests of good writing. Once surprise has disappeared, mediocre writing has nowhere to hide. You already know who the murderer is. You know who gets married, who leaves and which joke is coming. What remains is character, dialogue, humour, emotion, performance and construction. A genuinely good series can become familiar without becoming disposable. You aren't watching to discover what happens. You're returning because you enjoy how it happens.

If somebody is scrolling through their phone during the supposedly devastating climax of your brand-new thriller, perhaps their attention span isn't the only thing that deserves investigating. We can blame TikTok, dopamine and the collapse of civilisation. Sometimes the scene might simply be boring. Great storytelling makes a quiet deal with its audience: pay attention and I won't waste your time. It trusts us to notice things, remember things and occasionally work things out for ourselves.

Different programmes make different demands, and repetition sometimes has a purpose. The question is whether yours does. Has the meaning changed? Is there a payoff? Or are we terrified Darren was looking at his phone? Darren may indeed have been looking at his phone. Darren has made his choice. The writer's job might simply be to write something good enough to make Darren put the bloody phone down.