The entry comes from the 1865 Illinois State Census for Cooperstown in Brown County, page 55. The actual images are housed on FamilySearch.
The entry of interest is the second one on the page, shown partially in the image above (click for a larger version). Those three dots are not ditto marks--they are a "footnote" to the entry on the far right hand side of the page, shown below.
The "remark" indicates why the entry is "anonymous" and also makes it clear that those marks can't be ditto marks as not even the last name of the person is known.
It reads:
"A family just moved in--absent from home & no person new[sic] her name"
It is not often someone appears as anonymous in a census. The entire image is posted below for anyone who would like to see it.