Dancing and celebrating in the shipyard on the occasion of the completion of the ship in the background.
The impressum says the poster was designed by 满生, 洪志, 成翰 合作 - Mansheng, Hongzhi, Chenghan in cooperation. Mansheng and Chenghan probably are Guan Mansheng and Lin Chenghan. Both were active in Liaoning, where this poster was published. Hongzhi is not identified, unfortunately.