There is no moving parts, the shape of the model is just a cube.
There is parts though that change,
the display port needs to display the current item the TE is holding within it. (drawing the current item over the defined area)
There should be a progress bar that display the TE current progress with the item. A simple 0,25,50,75,100 state works here.
Any Item can be added to the TE, The item can change over the life of the TE and it could be empty.