The output size of the first cell cannot exceed 5 MB in size, forcing the job to fail.

The reason for the job failure cannot be determined solely by the size of the output as there is no limitation on the output size of the cells in a notebook.

The individual cell output is limited to 6 MB which caused the job to fail.

The output size of all the cells in a notebook should not exceed 20 MB. Since the total size of all the cells combined is more than 20 MB, the job failed.

The job failed due to multiple reasons as the size of any individual cell output in a notebook cannot increase by 6 MB and the total size of all the outputs cannot be more than 18 MB.