We used to be able to add comments directly from the Activity Stream on the Dashboard without having to go into each ticket to add comments. This function is no longer there although both Atlassian OnDemand and Standalone documentations say it should be:

• Adding the Activity Stream Gadget - JIRA
• Adding the Activity Stream Gadget - JIRA OD

Even with all permissions enabled, you can no longer add comments.

Current activity stream

Documentation activity stream