Mostly about how Google, Facebook and such can target different social groups when showing ads, and how ads buyers can choose which groups to show their ads to.
Ending in a flaccid unactionable generalization: "many platforms boast that they are free; in this context, it means that we are the product that being sold. We need a digital economy where our data and our attention is not for sale to the highest bidding authoritarian or demagogue."
And the annotation to the video says: "In an eye-opening talk, she details how the same algorithms companies like Facebook, Google and Amazon use to get you to click on ads are also used to organize your access to political and social information." Eye-opening my ass.