The shuffle mode for your current playlist is a toggle between the following options:
No Shuffle (Grey Crossed Arrows): Play through your current playlist as it has been established or saved.
Shuffle On (Blue Crossed Arrows): Randomizes the current playlist, including the current song and insert point.
The shuffle button scrambles your current playlist randomly each time, so deactivating and reactivating the shuffle option will re-scramble your currently active playlist each time.
While active, The option also pre-scrambles any playlist you add to your current queue.
This option is located at the bottom of the Play Queue on the Now Playing Screen. If using a Smartphone, select List Mode when displaying the Now Playing Screen.