The demo reported by Machine Heart begins with a simple scenario: a doll is placed too high, the robot cannot reach it, so it brings over a step stool, stands on it, and takes the doll down. It looks like just "stepping up a bit," but moving the stool, stepping onto a height, and reaching for the object—each step changes the body's support conditions.
The report uses a step at the kitchen entrance as an entry point: to a human it is one step, but to a robot it is a round of support transition—one foot lifts first, the other braces the body, and after landing the center of gravity is shifted over. With the two feet not at the same height, the body cannot continue copying its posture from flat ground.
YuanCe's self-developed S0 whole-body control system coordinates foot trajectories, torso posture and center-of-gravity shifts. According to the report, stepping into the kitchen and bending down to pick up objects on the step both test body control when support conditions change. Reaching the doll after climbing is a further benefit; what must first be solved is that with the ground beneath changed, the body can still act stably.
It should be noted that all of the above are demo descriptions of a vendor-release nature; the source gives no quantitative performance metrics, nor does it state whether the demos were completed continuously and autonomously, or whether they included human intervention or editing.