A1: First corners side R. Set and turn single.
A2: Second corners side L. Set and turn single.
B1: First corners cross R; second corners cross R. Take inside hand with neighbour: step back, step forward; cross R shoulder with partner, big loop R:
B2: R-hand star, taking 12 steps rather than 8 (6 bars); turn single L.
Most people use swirly siding, as does the animation.