The poem sets two images side by side: the public figure and the private one. At first we see the pimp as he wants to be seen, a "pleasure merchant" in a suit with gold buttons. The phrase is slick and a little ironic, since it dresses up what he does in the language of trade and glamour. The flashy clothing suggests someone performing success.
Then the poem turns. He is "only gentle alone late at night," and that word "only" matters. It implies his gentleness never shows when anyone else is around, and perhaps that he can't afford to show it. The last line, with its bottle and wine, leaves him in a quiet, lonely scene. It's unclear whether the wine is comfort, habit or escape, and the poem doesn't say.
The speaker doesn't seem to judge him harshly. The tone is observant and quietly sympathetic, and the mood is hushed and melancholy. In just a few lines, the poem lets us glimpse a person behind the role.