Focus on A Youth with a Jug and analyze the Kannekijker.
The painting depicts a kannekijker, one who peers wistfully into the bottom of an empty jug as if by wishing more wine will appear in it. The painting is unsigned, but the chemise of the boy is similar to that of another painting attributed to Leyster in the Bristol Art Gallery.The painter Frans Hals also made a youthful kannekijker in his Two laughing boys with mug of beer:
Bristol Art Gallery Two laughing boys with mug of beer Frans Hals