There are lots of ways people can be influenced subconsciously in a way that impacts behavior. For something that seems less political, we can think about marketing, which is essentially the science of getting people to do what you want while thinking it was their choice.
This is from a book I read about the obesity epidemic.
"It might surprise you to learn that music can affect our consumption of beverages. In a study conducted by Western Kentucky University’s Dr. Ronald Milliman, researchers compared the effects of slow and fast music on the behavior of restaurant customers. They found that people lingered at restaurants longer when slow background music was piped in. Patrons spent about the same amount of money on food as those listening to fast music but ordered more drinks from the bar, spending 41 percent more on alcohol.
Customers in wine shops have been shown to be influenced by music as well; in one study, patrons were more likely to buy French wines when French music played and more likely to purchase German wines when German music was played. In another study, patrons spent more money on wine when classical music was played.
In an experiment by Professor Adrian North, previously of Heriot-Watt University in Edinburgh, restaurant customers treated to a soundtrack of classical music racked up bigger bills than customers listening to popular music. The classical music listeners were also more likely to order appetizers, coffee, and dessert. If asked, I’m sure none of these customers would say that music had anything to do with whether they ordered a cappuccino or tiramisu. But atmospherics certainly affected their food consumption."
- A Big Fat Crisis, Deborah Cohen
It shouldn't really be surprising if other entertainment media also has some kind of impact on people, though people might disagree about what that impact actually is. I am taking it a bit further and saying things like the people you spend your time with also have an impact.
A lot of times individual people would rather reject that there's any impact or, at least, that they are above this trend even if other people aren't. This is because they want to have an identity of themselves as a rational actor who is fully and consciously in control of all their choices. People will likewise reject near universal psychological biases that have been thoroughly confirmed by research for similar reasons.
However, if you accept that you're not like this and instead are influenced by various factors like subtle emotional associations, then you can practice self awareness. This means you will notice at least some of what you would have not noticed if you rejected the possibility out of hand. When you notice this, you can counteract it with a more deliberate message to yourself (eg, "I don't need to buy German beer specifically just because of this music") or decide that you don't like the influence X is having on you and you will avoid it ("I will buy the wine online instead").
Accepting that there are subconscious influences also means you can stay open to the idea that you were influenced to make a sub optimal response or decision in a way you didn't notice, which means you can reevaluate past behavior to see if there was a mistake. People who think they cannot be influenced will often double down on the behavior instead and try to find someone else to blame.
This doesn't mean that, say, watching harem anime has whatever particular impact some random person on twitter says it has, but I do think it is going to have some kind of impact. I don't know if that makes sense, but this is at least my understanding of how this works.
