When a man becomes a king, there is an enthronement ceremony. And in any enthronement ceremony, the King receives a set of gifts that symbolize his position. He is given a crown to adorn his new position. He is given special clothing to elevate him above other men. He is given acclamation to show that he deserves the praise of all.
Jesus received all of these things. The crown of thorns adorned him as a man of sorrows. The purple cloak elevated him above other men as a high priest. The acclamation stated his identity and the worthiness of praise.