The CFD shows where you have a potential road block in your workflow. The width of each of color represents how many work items are in each step of your flow, from backlog through done. What you are looking for, and what you want, is generally a steady width of color for each of those steps, except for the first and last step. Eventually, as backlog diminishes, then the color will decrease while the color in done will increase. The middle steps all should have generally the same width across time until work begins to lessen. What you don't want is the width of one or more steps to increase.
Interpreting your data here, generally, your work steps appear to be flowing nicely, except for "review." You can see the width steadily increasing. Is it a problem? It's unknown at this stage because you need to see if it there is a steady state in the review step of your process. The growth in the width may stop now and remain steady throughout your work period. But it requires watching closely to see if there is something going wrong with your review step such as not enough staff or other performance issues.