pretty sure thats just some ornate bondage furnature with a regular human girl tied to it.
It's a statue of a mermaid, with a human girl making up the human part of the statue. Since the overall sculpture is of a mermaid, and sculptures are generally tagged with what they're a sculpture of if they're the focus of the picture (post #1262792, post #1580818), I think the mermaid tag is appropriate.