A yellow cube and a purple cube are placed on the table together with a marked target ring.
Using both arms, the robot stacks the cubes inside the ring in a fixed color order, the yellow cube first and the purple cube on top.
A trial is successful when both cubes are stacked in the correct order within the ring.
The per-phase change of target, together with the bimanual handoff, makes this a test of phase-dependent sequencing.