Hi Richard,
It is a circular 'motion' as opposed to the literal shape. As your hands reach the top and bottom, make a smooth rounded continuing motion as the lower hand moves in, and the upper hand moves to the outside. It is actually more of a flat elipse, or cartouche shape.
Difficulty in visualizing the energy is common. It improves with practice. Experience it like relaxed, but focused daydreaming. Read previous posts, there might be ones that address this. best regards, gallen
