Many ukiyo-e paintings and prints focus on <em>bijin</em> (美人), or “beautiful people.” Female courtesans and entertainers were the main draw in the pleasure district of Edo (now Tokyo), but young men were also available. The poem here reads as follows: "The full blooming cherry / is not the only flower worth mentioning. / The color of the young plum tree / blooms as well."
The full blooming cherry is a metaphor for mature women, and the plum for young men.