"Full screen caller" has two modes: picture mode and caller info mode. Depending on the selected mode "Full screen caller" will show either a photo associated with a corresponding contact or detailed information about the caller.
When "Full screen caller" is turned on, it shows a big photo of a caller or caller info screen during a phone call. A picture can appear during incoming or/and outcoming calls.
In picture mode "Full screen caller" tries to get the biggest picture from "Pictures" during a call. If there is no picture then the program will try to get a big picture from Contacts application. If there's no big picture in Contacts it tries to get a picture from "Pictures" for a group. If it doesn't find any it shows a thumbnail or default picture.
In caller info mode "Full screen caller" gets information about a caller from contacts database and shows fields that you set in settings dialog. [/img]