Inside each streaming node of an Azure Stream Analytics job, there are Stream Analytics processors available for processing the stream data. Each processor represents one or more steps in your query. The processor diagram in physical job diagram visualizes the processor topology inside the specific streaming node of your job. It helps you to identify if there is any bottleneck and where the bottleneck is in the streaming node of your job.

To learn more about it, see Stream Analytics job diagram (preview) in Azure portal – Azure Stream Analytics | Microsoft Learn