Use of the menu option File -> Import Pictures... is intended for use post-Gedcom-load, it will aid you in adding pictures that were referenced by the Gedcom but not initially loaded. (b/c Gedcom's are text based).
The [+] button at the bottom left of the pictures panel will allow you to enhance and crop pictures or add notes and source references to the data record.
Dragging an image from the pictures panel to another person on the context diagram will copy the image link. The image can be recropped for the second person's profile.
Images are by default copied into the ~/iFamilyData/Pictures/ folder.