THere's also the fact that any subgroup of the norm gets lumped together, which is what that guy is disliking. "What do the [insert minority group of choice here - cyclists, nuns, whatever] think?" My approach to that is being visibly unique.
Judging from your photo, you've accomplished visual uniqueness, and I think I've gotten a little bit of the answer why you're outside the norm, but I'd like to make sure what you're intending is what I understand. Are you trying to avoid being lumped into a given group?
My experience with most cyclists is they are comfortable being outside the norm in more ways than one. (I tell people that I'm not a non-conformist, just a poorly trained conformist.)
On the flip side, gaining the respect to engage in a dialog requires some common ground. I sometimes struggle with how far outside the norm is best, but as mentioned before, the smile let's you venture farther.
I'd like to avoid assumptions being made that all members of the group are more homogenous than they are; the classic example is when drivers say "cyclists are all red-light runners" or assume that we'd rather be driving if it's transportation, or that we're using the highways their tax dollars have paid for, for our silly recreation. The Xtra just makes people think 'cause it looks so weird. I'm totally comfortable being outside the norm - but would like to change some of the behaviors of people inside selective transitory ones. I was also reflecting that having a common ground means I can enjoy and appreciate people with whom in other settings there would be significant friction and tension (and that yea, if we could just get everybody out riding togehter, we could have world peace ;)) And thinking about flags... if I wave a flag behind my bike, what will people assume? That I support everything that's been done in the name of my country? or that I believe in the abstract ideals ... or which arguable abstract ideals and what concrete manifestations thereof... and a huge frustration *is* conveying that it really, honestly Feels So Good to Ride!!! Not "aren't I a good person in my suffering" but DELICIOUS...