If I have a Workflow Task assigned to me from on-premise SharePoint, when I open the related document, I see a WORKFLOW TASKS: Please approve .... alert in the ribbon as shown below. This call-out does not show when opening a document in Office 365 that has an associated workflow task. I can kick off the approval workflow, which sends an email to the approver. The approver opens the document but the 'WORKFLOW TASK' callout is not shown.
This behavior can be observed from Office 2010 and 2013 when opening directly from SharePoint.
What am I missing?