The Same File Name dialog looks like following image.
You can click More button and more buttons can be selected, following dialog you will see.
There are a couple of operations you can choose when ExtremeCopy encounter same file name .
Replace means cover destination file by source file.
Replace All means will Replace all destination files by source file which file name as the same as the source file in current copy task.Skip means do nothing on destination file.
Skip All means do nothing on destination files which file name as the same as the source file in current copy task meet condition which is 'same size' and 'same modify time' if you checked.
Rename means do nothing on destination but copy the source file to destination folder with 'Copy of' prefix.
Rename All means will Renameall same file name when current task encounter. .