All those from Sheba will come; they will bring gold and frankincense; and will bear good news of the praises of the LORD (v6).It may be post Easter, but one can't help think of the Wise Men at Christmas. This is doubly striking when considering how Isaiah continues:
All the flocks of Kedar will be gathered together to you, the rams of Nebaioth will minister to you (v7).So, Wise Men and now potentially shepherds too. Obviously, the initial fulfilment of the prophecy lay elsewhere, but could Matthew and Luke have had this chapter in mind as they recorded the details of those early visits to Christ?
The wider context of chapter 60 makes this highly likely. It is about the light of the LORD coming to Israel in salvation from judgement. It is about the wealth and honour of nations being brought to them; and it precedes chapter 61 that Jesus applies to himself in the synagogue, confirming this section is at least in Luke's mind at the beginning of his gospel.
So yes, the gold and frankinsense were symbols of Kingship and worship, but perhaps first and foremost, they were signs of Isaiah 60 being fulfilled. They urge us as those from all nations to bow our lives before the King and lay all we have at his feet.