The inscription is a line taken from the Dream of the Red Chamber, in which Xiangyun (a female character in the novel) came up with this line at the literary competition held on Mid-Autumn Festival.
The figure in the log boat on one side depicts the Han-dynasty imperial envoy and traveler Zhang Qian, whose extraordinary travels were later embellished into legendary poems.
A similar white jade plaque, dated to the Qing dynasty, and decorated on each side with the same scenes, is illustrated by Fu Xinian, Guyu Tuoying (A Selection of Ancient Jades), Hong Kong, 1995, pp. 302-3, no. 181. The plaque has the same inscription as the present plaque, but with the addition of a seal, wen wan (play thing). On the side with the 'weaving maiden', the window is framed by a tree and a fence, rather than the clouds on the present plaque.