The Steam Client Beta has been updated with the following changes: General The ability to mark games as Private has been added to the Manage menu for games in the library. Read more about the feature here. Added a new "Privacy" page to the app properties dialog with the new Private setting. The "Hidden" option is also available on this new page. The option to reset overlay settings and cache data has moved to the new Privacy page.
but this pop up doesn’t have to do with a purchase, right? Isn’t it triggered when a friend opens a game? Which can be disabled on the steam settings.