When logging in for the first time when logging in with an email address, when the account is activated you get the “this is your first notification” notice with the rest of the page blacked out. If you create the account with a social login, that doesnt’ happen.
I noticed on another site, but confirmed it on try.
Hmm. But the on uxmastery, I got the expected behavior when I got the second notification and clicked its link in an email. Perhaps somehow the initial notification only happens when you follow the email link?