Hi,
To save trees and the earth, now all vendors do not supply thick printed manuals. You can find manuals in the following link:
http://h10025.www1.hp.com/ewfrf/wc/manualCategory?cc=us&lc=en&dlc=en&document=&product=5164453
Based on the following link, it uses SD card (very popular) and you can add, remove ... photos/pictures on that card like any external drive.
http://www.comx-computers.co.za/DF840-specifications-65103.htm
Regards.