Why clothing store customers can see the background board cash register sofa area at a glance after

This is not necessarily, since it is a clothing store, customers must also enter the store for the purpose of buying clothes and looking at clothes, and what they see at first glance after entering the store can only mean that everyone's observation point is different.

And I don't know what kind of layout this service store you are talking about, but many service store cashier counters have a front background, so it's not surprising to see them when you enter the store.