“I don’t think you would look ridiculous dressing up on a date, any more than you do wearing a shabbos outfit to a starbucks.”
So she would look that much more ridiculous in a wedding dress in starbucks.
Fact of the matter is that girls should dress nicely on dates. Wedding dresses is just really pushing it. Besides, if a girl is put together and is dressed in nice clothes i’d venture to say most Yeshiva boys do not get the difference between a shabbos to shul dress, shabbos afternoon dress, vort dress, motzei shabbos when you want to dress nice dress, etc. Girls just have to look good. They do not have to be in silk and chiffon and sequins and taffeta like they would be at a wedding.