It is unclear to me what the 1st dimension of a boxplot represents. The documentation simply states "This is the inner dimension, which defines a box." What does this mean? I assume it has to do with level of aggregation but what is actually going on under the hood. For example, say my data is at the city level but I chose state as the 1st dimension? What is then being shown on the chart? The percentiles of aggregated data?
