The woman didn’t point out for whom the "esthetics" was — for family or passersby, and it is hard to tell. And if there is a set tradition it means that window plants impress those who see the window from the outside.
Windows can be decorated with other objects too, for example with toys, figurines, unique things or fruits and vegetables. In these cases the marker "for us" or "for passersby" can be quite definite. If toys and figurines are turned away from us, it means that the windowsill for the owners is a continuation of the room, an additional shelf and sometimes even storage space. Thus you can often see nicely piled or just scattered folders and books on the windowsills of offices. But if toys face you, china ballerinas bow toward the street and souvenir plates are shown in detail it means that the window is an opportunity for the owners to welcome the street, to pronounce the distinctness of their family and flat.