When Kim Byeong In , King Cheoljong and Queen So Yong are drinking together and the King and Byeong In are clearly inebriated, Byeong In goes to pour wine into his cup, and on two occasions, despite there being liquid in the teapot, as the scene progresses, he continues to pour and drink despite there being no liquid going into his cup.
Under Queen So Yong's teacup there is a bar code. As this is set in the 1800's Joseon era, there should be no bar code. Barcodes were invented in 1952 but did not become widely used until the1980s.