cpanel , cabinets or what you want picture will be displayed only if the layout you are using has been designed to display "dynamic Custom" objects.
What layout do you use?
You can modify or build your own layout using AtomicLayoutEditor , the objects that manage displaying of mame extra are Snap object (match with snap folder) Marquee object (match with marquee folder) Dyn Custom objects (match with custom dirs).
Of course you can use for instance MArquee object to display flyers if you want. Atomic don't care of what it is , it just look for the adhoc image in the given folder.
For documentation, did you check documention that are online on my website? Have a look to the old documentation too , may be this part is more described (not sure).
Did you see there is a dedicated AtomicFE support forums in english , here :
http://spaceinvaders.7.forumer.com/It would be nice ,to have all technical question concerning Atomic posted on that forum , just to centralize all information.
Anyway, that's not a problem for me to answer here. It is just for others what are looking for information it easiest to search in only one forum.