Ok, here comes another plug for the blog about self portraits that I curate.
Here’s the definition of self portrait that I use for that blog:

“Definitions of ‘self’ abound, and clash and overlap in various fields: psychology, science, religion, philosophy. There is also some disagreement as to what a ‘self portrait’ is.
For the purposes of this blog I am using the broadest possible definition of “self portrait”: regardless of medium, a piece is a self portrait if, by its author, it is considered representative of themselves, or of a part of themselves, and/but also those images where the author considers themself a model.”

It’s called strata of the self.
And yeah, ‘selfie’ is a dirty word.