So I read the second link and it looks to me like this is a combination of problems: the browser ignoring SOP for images, and the website just happening to expo

So I read the second link and it looks to me like this is a combination of problems: the browser ignoring SOP for images, and the website just happening to expose a way to abuse that fact to check if one is logged in. I think this also assumes you are not using any kind of isolation for your tabs. What I don't understand though, is how it could figure out that I am logged into google even though I have third-party cookies disabled.