>>280537892
It's a reference to ヤスヒ腰
YAS is Yasuhiko Yoshikazu, chara designer of the OG Gundam
He used a very distinctive contrapposto, a classical proportion tecnique where the body stands with most of its weight on one foot, so that its shoulders and arms twist off-axis from the hips and legs in the axial plane.
His contrapposto was very forward balanced, giving characters in standing an almost twisting pose
If you watch OG Gundam when characters turn and twist is VERY noticeable how much their weight shifts due to this chara design
It was quite influential back in the day