Apparently the dove is a cuckoo which also has kinda negative connotations in the West, and specifically a cuckoo who lives in magpie nests. Thus all the "magpie building the nest for the dove to live in" imagery.
Also there's a lot of controversy over how to interpret this: 1. The magpie/groom preparing a house for the dove/bride to live in. But then others say that magpies and doves are not the same species so this interpretation makes no sense 2. Magpie is abandoned wife and dove is the bride. After the abandoned wife built up the home, the dove comes to live in it, but there is no way for the abandoned wife to complain and thus it's all very tragic. 3. The magpie/dove are just some random birds and this is a poet who was a passerby and saw a wedding.
Re: Que Chao
Also there's a lot of controversy over how to interpret this:
1. The magpie/groom preparing a house for the dove/bride to live in. But then others say that magpies and doves are not the same species so this interpretation makes no sense
2. Magpie is abandoned wife and dove is the bride. After the abandoned wife built up the home, the dove comes to live in it, but there is no way for the abandoned wife to complain and thus it's all very tragic.
3. The magpie/dove are just some random birds and this is a poet who was a passerby and saw a wedding.