Need to ask someone about a particular update they made? You can respond to activities directly by tapping/clicking the "..." icon on the comment.
To reply to the comment, click on "Reply".You can respond to activities from the activities panel on the home page, in workspace activities, collection activities, or item activities. The user who performed the activity will automatically be @mentioned so that they're notified of your comment.
The response will appear as a comment on the item. The comment will include the activity it replied to.