Whistling With A Specific Porpoise

(I work as a cashier. It’s a slow Monday, so I’m at the front tidying up shelves. A woman wearing dark sunglasses and holding the harness of a dog comes walking in and stops about five feet from the door.)

Me: “Hello!”

Woman: “Hello!” *starts whistling loudly and walks a few more feet into the store* “Mom!”

Me: *raise eyebrows*

Woman: *sees me looking at her* “It’s okay. We have echolocation!” *starts whistling loudly again*

(After a few more seconds, nobody has answered her whistling.)

Woman: “Nope. Not this store.”