I was skimming through a web forum for people who care about and work on a particular type of car (E46Fanatics, for a specific body-model of BMW, the E46, which looks like this), not primarily mechanics but instead owners who maintain and work on their cars -- car modders, essentially -- and I noticed that a lot of them would, as part of their post (and probably part of their .sig), include a photo of their car.
This is in part because their car is something they have modified since it came off the showroom floor and, although it may not exactly be unique, it is probably unique or definitely quite rare in that specific configuration. (We're talking rims, tints, suspension, trim, some things you can't see so easily in a shot of the body of the car, and some things I probably don't even know about.)
However, it is also in part because the car is part of their identity -- it is something they are proud of, something they may have had a hand in modifying (i.e., creating), and it is something that identifies them as a member of the community.
What struck me (was the tire that flew off the car... no no) was that this is the same behavior that some people who play MMOs do in their MMO forums -- in some cases people will post pictures of their in-game avatars. I think this has been written about academically, but I don't offhand recall by who. But it's easy to see the similarities:
- Posting/sharing the image
- Image is of the thing that the community is about
- Object in the image is made, to some extent, by the poster
The obvious and significant difference between these two examples are that one community deals with concrete objects (cars) and the other with digital objects (MMO characters), yet, the behavior is the same.
(EQII has a default sig image, I grabbed the generic "this is what it will look like" image which doesn't have the character image in it but is for my main. And, that's an E46 with three really nice non-standard features: the rims, the clear turn signal covers, and the spoiler.)