How can I add (my own) pictures?

Therefor exists 3 ways. First way you can click in menu in database module on "database" - "create new entry/modify entry" and edit the object. You can see this on the next screenshots.

Or you to provide the pictures for me (assumed you have the copyright) and I add it. In this case after the next update all Users can see your pictures.

Alternative you import an xml file from another user (they have the pictures already in the database) and have thus the pictures also in your database.