Good points. I consider a "3-fingered selfie" a euphemism for my specific method of asking for a selfie. I ask for a pic with today's date with my client name on it. It is that simple yet specific and hard for pic stealers to get any benefit from it. I only request it from new guys to me. Guys with established reps are a totally different deal.
By the way, If anyone hesitates, I offer them my own client references - I have several regulars (escorts) who will vouch for me with new escorts. it is totally normal for an escort to think you are playing games, so the minute I offer my references, their fears lessen - some check my references, some just send me the selfie. Some decline and I politely thank them for their time and tell them that if they change their mind to hit me up.
I go thru all these extremes bc fakery is sooooooo out of control these days, selfies are so easy, and websites don't care or don't know how to prevent this fraud.