The Circle Activity feed shows all (direct) changes made or comments written within this circle. Unlike the personalized activity feed this feed shows all changes, not regarding who this is relevant for.
Each change log or comment will be shown as a line with user, type of change and the item this change was made to and finally when the change was made. To see the details of the change log or the fill comment, click the pop up icon marked with the red circle. It is possible to navigate and see older changes by scrolling to the bottom of the dashlet.