Many versions of this composition are known; the best, signed 'F. van Mieris', is in the Mauritshuis. Van Mieris’s training in Leiden with Gerrit Dou is revealed in this work, which follows exactly his formula of a single figure emerging from an illusionistic stone window, compare especially CW 43, 404621, CW 44, 404803 and CW 45, 404618. ‘Homo Bulla’ (‘Man a Bubble’) was such a familiar concept in the period that the phrase is used as the title of paintings even in inventories (which are purely functional records of assets). The idea is that a man’s life and all he cares for are so transient that they have no more substance than the bubble that shimmers delightfully for an instant. In this case the theme is supported by the idea of innocence and experience, youth and age: the contrast of the unreflecting boy with his mother smiling at his feather-hatted folly from behind. There seems also to be a contrast between blooming and withered flowers and leaves. The only solid thing is the window frame, perhaps reading like a monument, which similarly makes permanent a transitory thing (a date) but only to record one that is dead. The snail is a puzzle. Dated on ledge: 'M. DC. LXIII' (1663)