Hi Robert,
It is that it is showing 12,758 visitors your site on the 14th Jan. Of those 12,758 people, 697 returned on the 15th Jan.
Of the 12,758 people, 349 returned on the 16th Jan.
You can also right-click on the cell and "create segment from cell". This allows you to see the exact logic that Adobe are using.
Thanks
Dave