Just to clarify that I am understanding correctly: You want the shadchan to ask you if you would be interested before asking the guy?
Because if yes, then they can go and show your pic to the guy and ask if he wants.
Otherwise when it is the other way around, you feel pressure to reply because he already said yes and you know that even taking time to think about it means that he is potentially waiting around for your response.
Maybe also: You (and other women) are under more pressure to say yes to a guy who would otherwise be a no if you could anonymously have the first say.