[nexuist]

> So evidently it even looks at how long you look at certain content

It does. Instagram constantly sends back telemetry including your scroll position, which can then be used to determine what you were looking at and for how long. Scroll right past an ad? you probably won't see it again; the algorithm knows it didn't have an impact on you. Meanwhile, spend a few seconds reading what it says, and this teaches the algorithm that you are interested in similar content.