> Now, go away, or I shall taunt you a second time-a!

That is the implication. The point of the first fine isn't to actually hurt Meta. It's to signal that there will be consequences, that the excuse of "but we thought it was legal" is gone now and give them one final chance to get their act together.

It's to pre-emptively clear away any possibility for Meta to appeal to either higher courts or the court of public opinion that they're being treated unfairly. Which they would do if you immediately hit them with a say, €5 billion fine.