Here's the glossary definition from the Enformationism website :
An idea—a virtual stand-in for me—created by the sub-conscious mind to represent the person (subject) in relationship to other things (objects). ~ Like an Avatar in a computer game. ~ As far as my mind is concerned, the self-concept is the essence of who I am. ~ Equivalent to the religious term: Soul.
Here's another angle on the same concept :
I call the combination of Soul & Mind-patterns the "Self", which is the holistic conception of You.
Perhaps I should clarify that I think "Soul" and "Mind" are natural, emergent properties or functions of Body and Brain---not add-ons via divine intervention. But the Self-concept (self-image) is more of a voluntary construct. It's essentially a belief about the believer.