"Den Lille Havfrue"—the original tale of the little mermaid by Hans Christian Andersen—is a dark, eerie story with a sinister message of “careful what you wish for.” The little mermaid falls deeply in love with the human prince whom she saved from drowning. She sells her voice and tail to the sea witch in order to become human, although each step makes her feet feel as if she was stepping on knives/glass, and bleed. She is willing to suffer for his love, only to discover that he’s engaged to another woman. Since she cannot gain his love in order to become mortal—she knows her fate is doomed, and turns into foam.
The message—"careful what you wish for"—turns the mermaid into a victim of her own desire. The transition into a human being reveals her suffering pain as if she's stepping on knives, conveyed here by the glasses protruding from her legs.