Auto undock

I find this feature fascinating. When I drive my mower out of the charging dock it doesn't move at all. Instead I am offered two options:

1. Manual control - which is what I want and have already selected.

2. Auto-unlock- a clever "feature" that drives the mower forward 1m and only then gives you manual control so that... what? Why?

Can anyone suggest why auto-undock exists? What it just a product designer's fever-dream?