פירוש על קידושין 81:5

Others say that it is actually prohibited to betroth a woman through an agent. While one who betroths a woman in that matter is betrothed (i.e. the betrothal is legally effective), the act is still prohibited. The problem with the act is that a man must see his wife before he marries her, otherwise he might see her and decide he does not want to be married to her. Seems like a reasonable request to me.