Where as most of the workflows and business processes in an organization happens around document(s) only, but in Alfresco Share, the document is not shown in the task window itself.
You have to go to the document previewer page altogether to read about the document, and then come back to the task window for performing any action.
This flow may be very cumbersome to users to Review and Approve a document using moving around a couple of pages and doing a number of clicks.
This Add On renders the full document previewer (as in the Share document previewer page) and document properties section in the task window itself.
Thus the user does not have to navigate around a few pages to review the document and approving it.