If the request failed, this is the error message that was returned from the sub-process.
For result type of plot, this is the data that was returned from the sub-process to show in the plot
For result types of data, this is the data that was returned from the sub-process to show in the table
Whenever Skip executes it's analysis phase, it uses a sandboxed sub-process to execute code securely and this shape of data is used to communicate the results of that sub-process back to the Skip API server. This data type is in turn used within the SkipAPIAnalysisCompleteResponse type.