I don’t think it’s that unusual. I have two friends, one male and one female, who really strongly dislike having their pictures taken.
Lemme see if I can articulate the important differences between looking at a person and taking a picture of them, not necessarily because I have a big issue with your analogy, but because it really started me thinking.
How conscious is the act? People look at other people all the time because we are social creatures, and that’s what we’re wired to do. As you’re walking through a crowd, you’re constantly looking at the people you, for many reasons. You look at people when talking to them. If you’re just sitting somewhere in a group of people, you may be lost in thought and not even be aware that you’re looking at another person, but as humans, our gazes are drawn to faces. Contrast this with taking a photograph, which is a very deliberate act: raise the camera, frame the the shot, press the button.
What is the utility of the act? Looking at people gives us a lot of valuable information. Where are you, so I don’t run into you? Are you angry, so that you might be a threat to me? Are you doing anything that intentionally or inadvertently threatens my safety? Are you gesturing to get my attention? In conversation, a lot of meaning is conveyed by facial expression, gestures, posture, and other clues we can only get by looking. So not looking at you may be inconvenient to me, because it costs me a lot of information that could be useful to me. Not taking your picture? The only cost to me is that . . . I don’t have a picture of you. What is the value of that picture to me? If you’re a stranger I just met at a con, very little.
Do I know that you do not want me to take this action? Most people do not want me to walk up and punch them in the nose. Most people do not mind if I look at them, and if they do mind this a lot, they are probably aware that if they are in a public place, people are going to do that anyway, and are dealing with it. People’s feelings about having their picture fall somwhere between these extremes, and vary. Most people, at least, would like some warning that their photo is being taken, so it’s reasonable to ask, “May I take your picture?” But it is silly under most circumstances to ask, “Do you mind if I look at you?” and because looking something we do so constantly, it would be totally impractical to get the permission of everyone we look at.
How long-lasting are the consequences of the action? If I look at you, then I have a memory of you. I could maybe tell other people that I saw you, or give a vague description of you. I wouldn’t be able to draw a recognizable picture of you, and most other people wouldn’t, either. If I take a picture of you, then I have a permanent record of your image, which I could show to other people, manipulate, duplicate, and distribute without you having any control over it.
Either way, if you were to politely say, “Please don’t take my picture,” or “Please don’t look at me,” then I wouldn’t, because I have been informed that it bothers you, and it’s fairly easy for me to comply with your wishes. If you’ve asked me not to look at you and I accidentally glance at you, I hope you will forgive me. But if you’ve asked me not to photograph you, and I do take a picture of you specifically, not just accidentally catching you in the background, then that’s more akin to deliberately staring at you after you’ve asked me not to look at you, which is just freakin’ rude.