It Is a Google thing. It’s a script that Google gives to third party to promote logging in with their account, and it can access Google cookies, so it can get populated with your name and email (which is absurd as some other malicious js on the same page could parse the HTML to extract the personal data of the user without consent)

If you’re logged in, there’s a setting buried in the Google account (really buried, very difficult to find) which hides this nag.