This is the AR version of the VR movable menu panel, so it follows the same principles in terms of purpose and design:
Be able to place an interactive panel in a particular location in space (i.e. move it to where it’s needed)
Have the panel options remain in the desired spot until I’m done using it (i.e. I can place a menu where it’s convenient, not getting in the way and where I know I can find it and easily see it when I need it)
The UI design principles regarding the panel size and behaviour are the same for VR and AR. The interaction is described already for the VR version of the pattern. The main difference is that for it to work in VR the HMD must be capable of tracking the hands, or some other object that is used to move the panels around.