Log in to the admin client
1. Open the Site explorer three, which you can find in the side-menu under Site explorer
2. Right-click on an object
3. Select "New sub site object"
4. Choose a category
5. Set a Type
6. Enter a number
7. Enter a name
8. Save the object with CTRL+S or File/Save 
9. Go to the Description tab
10. Select the Pictures subtab
11. Select Edit picture/Add picture
12. Add the picture to the object
13. Click Save and close
Now you have created a new object