there is no commonly agreed upon, not to mention followed, practice concerning this.

 
Originally GFE was used to denote a kind of session where the provider would act as if she was your girlfriend rather than a soulless stranger as sex workers were often depicted in films and literature.   It didn't really have any particular activities associated with it.   In time, however, things like DFK became associated with it and also MSOG.   Today some are even saying that BB this or that should always be associated with it.

 
PSE, which began to appear around the same time as GFE, related more to activities such as you would find porn stars performing so greek, DT, and even BBFS became associated with it.

 
As always, these descriptors should be taken with some skepticism and reviews should be your main source of determining what you may or may not experience with any particular gal.

Porn Star Experience vs Girlfriend Experience

I'm not completely sure about Porn Star Experience, but I offer GFE which to me as a provider means:

🎀Lots of French kissing (I am a French Latina after all!)
🎀Possibly my lover going down on me
🎀Lover wants to make sure I cum as well
🎀Caressing and cuddles
🎀Conversations
🎀My bubbly warm personality

in addition to a hot passionate time hope this helps