Avatar self-portraiture on Flickr: Art or Onanisim?

What's up with the incredibly prolific avatar self-portraiture evidenced on flickr? Here are a few categories I've noted:

• The shiny new parent/lover/toy syndrome: I have a pair of childless human friends who got married and bought a small dog. I must have received links to a hundred or more images for the first couple of month: Dog on the couch. Dog in the yard. Dog in the boat. Dog with the cute hat. I haven't seen any research, but my guess is there is some logarithmic curve downward for how many photos are produced for subsequent pets, children avatars, etc.
  

• Neo-Narcissism: This applies to Immersionists, both open and closeted. It seems to me that if one identifies personally with the avatar form, then having a gazillion photos of oneself on display on flickr is equivalent to a human doing the same thing. Obsession with one's physical form isn't always ickishly shallow. Not always. And self-love can be a beautiful thing. Or self-lust.
  

• Avatar as canvass: For those with a bona fide artistic nature, or wannabe's like me, we will never find a more patient model than our own avatars. They will pose for hours without complaining. They never ask for a royalty check. Although they may not be easy to work with, it's certainly a familiar and comfortable relationship. And you always get to sleep with the hot model, right?
  

Although this is a somewhat tongue-in-cheek post, my guess is that there are multiple elements at work in many of our photographic exploits. Did I miss any categories, whether serious, semi-serious, farcical or otherwise?

Have a good weekend.