Erm.. No, its not. A selfie is a picture of yourself. I.e. You. Not someone that looks like you :D

Is this question on a genetic level?  I mean identical twins have the same gene set up or something, don't they?  I'm not a biologist or whatever I got know clue.  But if they are the same on a genetic level... then yes.  And if "no" then are we saying selfies are photos of one's spiritual self?  

No, no - genetics have no connection to the answer. The term selfie is defined by the 'self' i.e. the person's consciousness. Even if genetically identical clones, they experience life as different consciences - therefore twins taking pictures of each other would just be another regular shot for the album. 

No - different person but if one had just donated an organ to the other it might make for an interesting case since part of them would technically be in both then.

If you believe that Twins share a soul (and a consciousness)  then it would be a selfie.   But it would be like taking a selfie of only half of your face.

I think you're also asking about identical twins. If they're fraternal and of the opposite sex, then definitely not a selfie. 

And with Identical twins, most will tell you that they aren't fully identical. They have a scar that's different or slight variations where they can instantly tell each other aprt. 

No because as you stated in the question.... "If twins take pictures of each other are those just selfies?"

Take pictures of each other...not of themselves, which is the definition of a "selfie".

sel·fie

ˈselfē/

noun

informal

1. a photograph that one has taken of oneself, typically one taken with a smartphone or webcam and shared via social media.

But I do find identical twins fascinating.  Trying to guess which one is which because everyone has their own unique individual quirks and whatnot to be identified by. 

If object/person 1 takes a picture of object/picture 2.. it is in no way a selfie.