The reason to use this type of framing grid is to capture the center of an area or the most important part of an area. We don't want the most important parts to be too high up or too low down. This is a good framing tool for a portrait, for example.
In the example, the image of a fish swimming sideways is in the center of the framing grid
The fish should not be too high up or too low down, as it cuts out of the framing grid. This helps to frame the point of interest. In this case, the fish is the point of interest and the framing grid helps to capture it in a centralized way.
The framing grid will help create a nice picture and frame it in a very nice way
This is something that is good to experiment with and see what happens. This can help improve your photographic techniques. It can help improve your style and understanding. Try it with portraits or other elements where the point of interest should be centralized. If you want to share those results with us, then please do so in the comment section below.