It is very much interesting, especially when used in the right context. Here is the meaning: traditionally food is served by a woman (wife) when a guest arrives. She is expected to serve the guest, in most cases the husband consents. In some cases she simply sits around while the husband expects her to serve the guest. He can't tell her what to serve in front of the guest, she should know on her own. This is a cultural norm (a custom, like anywhere else in Ethiopia, I think).
After waiting for the wife for a while the husband gives some signal, she ignores the sign. Then it gets more serious and the husband has to tell her what to do, she still insists, because she is more of a tightfisted or stingy person (which is what a ዶቅና means). The husband has to now handle and tell her in front of the guest "you should serve the guest" (now it gets more embarrassing for the wife but still she should also heed to the order of her husband). That is why it says a "tightfisted wife reveals her character first and then also forced to serve the guest what she didn't want to offer readily"
The husband is here the international community, it is waiting that the stingy Eritrea reacts to the expectation of Ethiopia and offer her what she is expecting and waiting politely.
The stingy wife Eritrea still refuses to listen and force may follow and Eritrea led by the old man would reveal her unhealthy character and then also forced to give what she is tightly holding on. Lose on both ends.