A photo doesn't neccesarily mean it's a photo of that person, so I don't pay much attention one way or the other. In fairness to some people, not everyone is comfortable with their looks or feels they may be judged unfairly if they have some handicap.

Over time, if someone contributes a lot, you get to know them pretty well by what they write and that's generally all I would care about.

I dont see the danger in speaking with someone via voice only. For a language exchange, image is not really necessary; some people are just not comfortable speaking to strangers face to face at first. It might be helpful in some cases to see the gestures and body language but it is entirely possible to have a productive conversation without video. Now, if the person has their camera on but hides their face, in that case, yeah, I would agree it is a bit strange but maybe not dangerous. Sometimes people refrain from using video during calls because it slows down the connection, other times, they just feel more comfortable without it. It's a matter of personality and preferences, I suppose. I personally don't mind video chats, but most of my interlocutors prefer voice-only and I am ok with that.

The whole world is not dangerous for blind people :)

Be dangerous or not depend of kind of conversation you have, a person can be dangerous with picture or without picture, and not just the men's but also the women's

"People who insist upon "hiding" are either socially backwards or those who could be a potential danger to others." Bruce

You have no objective evidence which shows that people without their personal potos could be backwards or danger to others.

Define socially backwards ? and Define potential danger? You can't judge all people by your norm!.

And what about superman or batman?!! is he also could be DANGER?!! ha!!

I show my face only and only if the other person ask for it. And I never ask someone to show his face if he doesn't like to. I do vedio chat if they want to. I am not going to force anyone otherwise. I remember here in italki once a girl from China started a discussion about someone from USA who made vedio chat with here but he was completely naked !!... Sometimes, people who focus on their beautiful selfie could be danger, beleive it on not. It is your choise.