Brazilians please answer.

I have seen lots of brazilian pros having their account name in riot official games as eu. What does it mean? any significance?

ex: less, cauanzin, saadhak ( I know he is from Argentina), aspas and someone from furia today don't know exactly who.

eu = me = I

I think thats just streamer mode where instead of it saying "me" in english, its "eu" in portuguese