For reasons too boring to get into I visited this old answer of mine. The screen shows an edit, and identifies the editing user as "user242" with no picture or link, typical of someone who has deleted their account:
Above my answer is one by that same user, which correctly identifies them as author, but also has the no-link-id-only identification for who last edited. Is this a bug?
Added. It does not seem to occur with the question itself, but that's a different editor. I guess one possible explanation is that it is the result of another account being merged/deleted at some point?