If an edit applies only to the title, the suggested-edit review looks like this:
followed by the rendered output of the question. In particular, the usual interface to switch between rendered output and markdown is missing.
Thus, a reviewer who is not aware of this, may be confused as to why this interface is missing and as to whether there were edits to the question body that are not visible in the rendered output. At least this is what happened to me and made me ask this question.
I therefore propose that the review window explicitly indicates if an edit only affects the title. Something similar applies to the view of the rivew item (e.g., here).
(I guess that this is rather easy to implement right now the view interface is replaced with nothing in case of a title-only edit and one would only have to change it to be replaced with title-only edit or similar.)