What are user icons for?

1. Helping you identify users by associating a picture (=face) with a name.
   My user icon is an example of this. It's not my face, it's the face of the actress who portrayed the character I named myself after when I had to come up with a pseud in a hurry, but it serves the purpose.
   
2. Helping you filter posts by users who post on many different topics.
   Many users have fandom specific icons, icons for stream of consciousness fannnish glee, icons for being thinky and all meta, etc. The best icons have a common thread, such as a particular artistic style or the name of the user written on the icon itself. Most seem to prioritize filtering by fandom over identifying users. That's oddly self-effacing.
   
3. Ad space for pimping or politics.
   For example the recent Dreamwidth and OTW campaigns, or the wanky OTP wars in SGA fandom a while ago. It's a useful method for viral distribution of a message, but not very helpful for identifying users. It prioritizes group-identity over individual identity.
   
4. Hindering you from blocking other users' annoying mood themes from your reading page.
   Some users have an icon to go with every mood. The only person in my experience to ever do it right is ratcreature, because much as that huge bulbous nose on the ratcreature thingy unsettles me, at least I can tell who she is.
   
5. Displaying the world's most horrible, juvenile, tacky, glittery, bouncy sticker collection.
   Yeah, don't do that. It's really annoying.

Dreamwidth layouts seem to take it for granted that no-one uses icons for the sake of helping other people identify them. The user name is on the left (= before the entry), and the user icon is unassociated with it, mere decoration. With some users, this is helpful to me. Seeing the user name in isolation, rather than in a new different combination every time, helps me recognize it as a unique identifier. With other users, the ones who care to use a consistent style of icon, I miss the strong visual coupling of name and pic.

Many of you probably think I'm being extremely silly and nitpicky about this, but that's because you don't understand that I genuinely have difficulty processing "same username + icon 1" and "same username + icon 2" as identical. I am strongly visually oriented, and images always trump words. (Written words form a visual shape too, of course, but the sameness of the font and the typical length of user names make them less obviously distinct that icons.)