Two shiney walls

A boy and his Father visiting from a third world country were at Lakeside
Mall. They were amazed by almost everything they saw, but especially by two
shiny, silver walls that could move apart and back together again.

The boy asked his Father "What is this Father?". The Father responded "Son
I have never seen anything like this in my life, I don't know what it is!".

While the boy and his Father were watching wide-eyed an old lady in a wheel
chair rolled up to the moving walls and pressed a button. The walls opened
and the lady rolled between them into a small room. The walls closed and
the boy and his father watched small circles of lights w/numbers above the
walls light up. They continued to watch the circles light up in the reverse
direction. The walls opened up again and a voluptuous 24 year old woman
stepped out.

The Father said to his son "Go get your Mother"