If you have the permission to do so, you may have received a warning email that a document has been inserted, or if not, you can click on Documents to be approved. You will see a simple list of documents not approved yet, you can choose one, review, and decide wether to approve objects in it or not.

Approval is on objects not on documents, because objects represent the real content. Further is a new object is added to an existing item, there is no reason to hide the whole object from public view until the new object is approved. By clicking on Approve object you get into a screen where you can insert a comment and press on Approve object button. This comment will be sent to the person who inserted the object, provided that the doc_appr event is enabled. This message will be sent also to any other people subscribed to this event.

If you press on the Don't approve object button instead, nothing will happen, but the doc_notappr event will be triggered. If this event is active, the person who inserted the object will receive this comment, together with any people subscribed to this event.