Perched among the marble curves of a decorative clock, a little mechanical figure of a woman presses her hands against her own unmoving breasts as the hours tick by. The speaker looks on with a pang of playful envy. That lifeless machine gets to touch what he longs to touch, yet for him, a flesh-and-blood lover, the same act is somehow forbidden. The poem turns on this witty, frustrated question: why does the clock enjoy a privilege denied to the man who actually adores her?
The mood is light but charged with erotic longing. Shelley treats the clock as “too fortunate,” as if it has stumbled into an intimacy the speaker can only imagine. The marble coolness of the statue and the mechanical regularity of time contrast with the warmth and urgency of human desire. There’s a teasing edge to the final line, half lament and half knowing smile, as if the speaker half-expects no answer but can’t help asking anyway.