This Mitre, from far away, is supposed to resemble a (papal) Tiara. That is the purpose of the three lines of jewls on it. Of course, the top will always look like a Mitre, even from far away, because it is a Mitre! However, the tiara (very different from the Papal one) is still part of coat of arms of the Patriarch of Lisbon. Check their website!
Now, this is a picture (very small, though) of the sedia and the flabella used by the Patriarch. The sedia looks smaller than the Papal one and not as wide. The flabella are much smaller, too.