The parent comment is a bit flip and sarcastic, but he's not wrong. $550k isn't even a speed bump for Twitter. SV tech companies aren't going to take EU regulatory bodies seriously unless they pass out meaningful fines.

Hopefully, Ireland’s Data Protection Commission intends this to be a "shot across the bow" hinting at more severe fines if Twitter continues to do this kind of thing. Otherwise, Twitter is unlikely to change their behavior.