Media XL startup animation

So far (fingers crossed) no big concerns with my April 2015 Cooper S Auto other than the need for a wheel alignment. But one inconsistency with the electronics is confusing me. I have the Media XL setup and, sometimes, when I start the car there's a very cool "animation" on the screen. Lots of swirling swishing lines and then the Mini logo. But most of the time it just goes direct to the main menu screen on startup. No cool animation. Hardly a big deal, but confusing all the same. What's it all about?