Practice deciphering the 4 part code to form a shape using your hands that mimics the 2D symbol. Also use the space in front of you to represent the upper and lower symbols on the slide to add shoulder mobility exercise.
The first slide has the code. After that each pairing starts with the 2D symbol
Still only 2 symbols on each slide but they are not so easily distinguishable from each other. Practice left and right handedness added to looking for a match.