Pictures of the controller keep the classic PlayStation 5 style, but show a few key differences. One of the biggest changes is buttons under the analog sticks, which allow you to completely remove the analog sticks; which Sony refers to as "removable stick units".
Another feature includes the trigger stops at the back of the controller, in addition to flappy paddles/buttons that have become increasingly popular over the years with players turning to companies such as SCUF Gaming and NACON for such controllers.
The prototype also features grips to help hold the controller, which also seems to be removable.