I took the people to each represent continents - Africa, Europe, Asia, and the Americas. So, I don’t see “Irish” as much as I see “European”. I took the theme to be showing how similar and connected we all are (via the thread).

The hint of colonialism / exploitation I see is that the European woman is holding her candle (representing culture) without fear, while the other 3 are cautiously protecting theirs, having dealt with attempts by others to extinguish them.