This is more like the compass for finding your way out of a geometry book. A mathematical compass (like this one) is used to draw perfect circles. For Donne, it was the perfect metaphor for the long-distance relationship he imagined with his wife. Line 26: The compass is introduced emphasizing two crucial features.
Third person, a lot use this perspective so you can see what every character is doing.
A story is made into a fable because it is a short tale and tries to address moral ideals. It often includes examples of whimsical characters, as they are usually for children, but also adults and teens.