Lots of people flag posts and, in the "Other" explanation, add links. The vast majority of these are of the type
exact duplicate of stackoverflow.com/questions/4275311
The only way to evaluate the exactness of the duplication is to click the link and view it in another tab.
Can there be, for links to the same domain, a quickie preview on hover? Title, the first four lines, and the user who submitted is usually enough to determine if the question is an exact exact duplicate which requires further moderator massaging (merging posts or users).