Show Duplicates vs Report Duplicates
There's a ShowDuplicates servlet which appears to be an older version of display duplicate files in the Audit Manager. In addition, the ReportDuplicates is only one which is accessible in the UI, so the ShowDuplicates likely hasn't been used in some time.
However, I'm not sure how the two servlets differentiate so we need to look at them in order to determine if there's any difference in functionality.