"Three Dreams in a Desert" is just that: three dreams that the narrator has while in the desert. I will give a quick summary of each.
The first is of a beast tied to another beast, both in the desert. One stands, while the other is down in the sand and hasn't been able to stand in for years and years due to a weight on it. The standing beast is Man, while the beast on the ground is Woman. The weight is destroyed in the dream, yet it still can't stand.
The second dream is of a woman speaking to a man called Reason. She is trying to cross over into a land called Freedom, but there is a river in the way. He instructs her on how to do it, but she must first detach a child suckling at her breast. She is reluctant, but Reason states that the child will fly over to her and meet her in Freedom. She then worries that she and countless other women will die crossing the river; Reason says that their bodies will then be a bridge for all of humanity.
The third dream is of men and women holding hands and seemingly being equal. It is deemed to be Heaven, while still being on Earth, and it ends by saying that this final dream will come true in the future.
While Olive Schreider is not always coined as a feminist writer, the three dreams of this little story definitely contain feminist ideals. The first demonstrates a shrewd understanding of how men keep women down and that women must learn to "get up" without the help of men. The second dream shows women helping other women reach a state of freedom via the bridge. It also shows that women do not need to be defined by their children. The final dream is obviously a beautiful one of gender equality, and Schreider presents it as being an attainable thing to envision.
Ultimately, the main idea here is that women should help each other get to freedom and should pursue freedom as much as they can. It's actually a really interesting story that feels ahead of its time!