This article did not explain what specific law was broken. Does Brazil have a law stating that all electronic devices must come with a power source? If so, Apple clearly broke that law. If not, what is the specific violation?
I'm not sure the specifics but yes, Apple has violated some law or regulation.
I believe it's related to a law stating that products must be sold in fully functional form without any tie-in purchase requirement, and a phone sold without a charger isn't considered a fully functional product - the requirement to separately purchase a charger would constitute a tie-in sale (however things can get muddy if consumers are not required to use a charger that's sold / manufactured by Apple).
Also, addressing some other comments - the fine might seem ridiculous but it was just the first one. If Apple doesn't fix the issue they might issue more (and probably higher) fines, and the violating products could be taken off the market.