Here's my two cents.
I believe I come with a unique perspective being that I am a single woman who's been dating for a while, as well as a sister to a brother who's been dating for a while (in yeshivish circles) and is heavily involved with helping my mother (so kinda bring the boy/boy's mom's perspective as well).
There seems to be 2 conversations going on here, I will address both.
Girl's perspective:
I've been asked for my picture countless times. I don't like it, but will send if asked. I've been asked for a full body picture, which I've adamantly refused to send and I think is appalling.
I don't like the concept of people having my picture on their phones. I've had guys who know me that try to work on ideas pull up pictures of me in front of my friends and examine them.
That makes me extremely uncomfortable.
For girls who are a bit less 'pretty' or attractive, I think it's doing them a disservice. People will meet them, like them and their personality, and in some cases, she will become attractive to him.
Pictures don't allow that and they will say no off the bat.
Boy's perspective:
My brother is young and yeshivish, so he does not deal with his shidduchim, his mother does that for him. She will vet the girls and many times receive pictures as well. He never looks at them.
We will generally use the picture to get a sense of the girl and 'her type' rather than focusing on how pretty she is or isn't. You can tell a lot from a picture and when you are receiving so many names a day, you gotta narrow it down somehow.
I see both sides of the argument, yet I strongly believe that the genie is out of the bottle on this one. It's 2021, it's an age of constant communication, texting, Whatsapp etc. If the girl won't provide a picture, someone will and it will likely be a less flattering shot.
Regarding going out a second time. This is something I vehemently disagree with. It is not offensive or rude to say no after one date. There is nothing wrong with the person I dated, he is just not for me. Why would I waste anyone's time?
Yes yes I know you know of your aunt's cousin's neighbor who said no and was forced to go out a second time and now they are married with 14 kids. I've heard all those stories.
Bottom line - you need to know yourself and/or your child. Some people need time, some don't. But it's not offensive. I am thrilled when someone says no to me after one date.
*steps off soapbox.