Often times am issue in Jira will have sub-tasks associated with it. An approval or rejection of an issue will also often times be related to the sub-tasks of the issue.
Were all the sub-tasks completed? Are there any missing sub-tasks that should be added to the issue?
It would be handy to have a way to put details from the sub tasks into the email as well so that the user doesn't have to get into Jira and research the issue to decide whether to approve it or not.