Why is Sister Xianglin in Qi Xin called salted chicken?

The word "salted chicken" is actually used to describe the cp names Ma and Ding, because the combined name of Ma and Ding is "Qi Xin", while "Sister Xianglin" refers to the names of another pair of cp Yan and He. This title may come from some specific fan culture or network culture, and the specific reasons may require a deeper understanding or asking specific fans or members of the online community.