"Girl Powdering Her Neck" is first a description: these are the details of how a woman—specifically, a Japanese woman of a specific period— prepares herself for the day. After that, it is a commentary on several things. It comments on the artificiality of it all; look, it is saying, at the work that's involved, the artifice involved in presenting a specific appearance. It draws a parallel between the kind of self-scrutiny involved in putting on make-up and the self-examination involved in critical self-reflection: it looks at how they are similar, and how they are different. They come together, or they might, then they part. That's the meaning of the final haiku stanza.