It isn't only a matter of how we are perceived. We see the painter paint us...or we think the painter is painting us, but we can't be sure that we are his model actually. Foucault pointed out that constant illusion in "Las Meninas".

It's the same in LJ, because we can never be totally sure that we are the one who's watched since what the others actually have on their canvas screen is conceiled and we can't be sure they are watching at all too !