I came to buy a smile to-day
Diminishment strategy
She keeps minimizing what she wants: 'just a single,' 'smallest one,' 'no one else would miss,' 'so very small.' Classic negotiating tactic—or the desperation of someone who expects to be refused.
Commercial transaction metaphor
The whole poem is structured as a marketplace negotiation—she's literally at a counter trying to purchase something emotional. Notice how 'afford' works both ways: can he spare the smile, and can she pay the price?
Jewelry catalog
She lists her payment like a merchant's inventory: diamonds (hardest substance), rubies (blood-colored), topaz (star-bright). Each gem escalates in metaphorical weight—from wealth to life to heaven.
Anti-Semitic stereotype
The 'Jew' reference invokes the 19th-century stereotype of Jewish merchants as shrewd bargainers. She's saying even the toughest negotiator would recognize this as a good deal—deeply problematic language that reveals period prejudices.
Formal distance
She calls him 'Sir' three times in this short poem. That formal address creates distance even as she's begging for intimacy. The politeness is part of the pain.