I used the "Cluster Behavior by App Usage" example in the Clustering Numeric Fields workflow within the Splunk MLTK Showcase. It produces the cluster visualization shown below. Can you help me understand the meaning of this visualization or recommend resources for understanding this visualization? How do I know which fields are clustered by looking at this? I understand the coloring has something to do with it, but there are multiple plots, and I would love some help trying to understand what this means.