Note the logo on the status window there: TrustArc.
A little searching for that company shows that this dark pattern is effectively a feature of their service. Twitter user “pixelscript” dug into their javascript a bit to find the cause of the delay. It turns out that, as you may have guessed, this isn’t any kind of asynchronous callback pause waiting on the remote server to do something. It’s just a self-imposed client side delay; because they feel like making you wait.