This happens often enough: a highly upvoted post is shown in review as a 0-score or downvoted post with user information anonymized (or sometimes replaced with an existing user's info, but one different from the OP). The intention, as with most audits, is to see whether you'd judge the post like most users here would.
To that end, visit the actual post, from the link in the sidebar. This will take you to the exact post that's used for the audit. The linked post is highlighted for a brief time when the page loads, the highlighting fades away quickly.
If no post is highlighted, then it's already been deleted and this is an audit. You can safely proceed to apply negative actions to the review post (delete, downvote, etc.).
If a post is highlighted, and the account and scores differ, again an audit. This will usually be an upvoted post, testing that you can recognise good content, so upvote or edit the review post. You're supposed to judge the post purely on its merits independent of other posts*. Considerations of plagiarism don't apply since these are the same post.
If a post is highlighted, and the account is the same, this is not an audit. Review as you would have.
* Which is nonsense. I've seen tons of upvoted crap and I absolutely refuse to click the I understand button after failing those audits. Petty, I know.