pretty girl who attracts customers to a shop
Refers to a young woman whose charm or beauty draws customers into a store, restaurant, or similar establishment. Often used in a light, colloquial way.
あの店の看板娘はとても愛想がいい。
The pretty girl who attracts customers at that shop is very friendly.
彼女はこの居酒屋の看板娘として人気だ。
She is popular as the attractive face of this izakaya.