Four concentric shells around an undrawn light, a tide of light: a swell is born at the centre and breaks outward on each shell in turn, flinging spray from the outer skin, then the water is drawn back inward as fine streaks through the same shells in reverse order, vanishing at Determination and re-emerging clear at Ground

Note the structure: Exoteric Wrath, Esoteric Mercy, Esoteric Wrath, Exoteric Mercy. This is the nature of procession, and then reversion.
The Structure of Nirvana

Emanation, outward →

← inward, Return

Emanation, outward →

Hold, and the water is drawn in.Release, and the next swell breaks.

The tide runs by itself. A swell is born at the undrawn centre and breaks outward on Ground, Determination, Mechanism and Actuality in turn, each shell performing its act: Ground and Mechanism inhale as Mercy, Determination and Actuality exhale as Wrath. Spray flies from the outer skin. Then the water is drawn back inward as fine streaks through the same shells in reverse order, each performing the same act again, vanishing at Determination and re-emerging at Ground. Press and hold anywhere on the figure, or hold Space or Enter with the figure focused, to draw the water in at once and slowly; release and the next swell breaks outward. The register names open their definitions at the foot of the page.

Fig. IV — procession breaks outward in waves; reversion is the backwash drawn home.