It seems to me that what he sees in movies is a narrative being programmed into the viewer.

What is a narrative? A collection of propositions. What is a proposition? Something is something else, or something is not something else. X is Y, or X is not Y.

>Saturated fat is unhealthy

is one example.

I guess one form of conditioning or programming is implanting propositions into people's minds. So for example "saturated fat is unhealthy". Like the "sleep-learning" in Brave New World. People would then have a programmed response, in terms of what they associate with a certain word or phrase. Every time someone heard "saturated fat" for example they would have a knee-jerk reaction to think "unhealthy".

https://youtu.be/BhIIPbO_6xg

But where exactly lies the danger? In the consequences of people's thoughts, ideas, behavior?

A proposition is either true or false.

"Saturated fat is unhealthy" is either true or false. Either saturated fat is unhealthy, or it's not. Every proposition can have its truth or falsehood supported by arguments. "Saturated fat is not unhealthy" is not an argument, but just a counterproposition.

Wyatt Stagg presents zero arguments against the propositions he claims are being programmed into the viewer. Again, where lies the danger? In people believing false propositions? Then why doesn't he present arguments for the propositions he believes are true, arguments against the false propositions in question? He never does.

https://archive.org/details/logicorrightuseo00watt