One of the highlights of last week’s ceremony marking Uli Sigg’s milestone $163 million donation of Chinese contemporary art to Hong Kong was a mysterious gift to the Swiss collector, brought onstage framed and festooned with red ribbons.

West Kowloon Cultural District Authority officials confirmed afterward that it was a work by Beijing artist Hong Hao, best known for his collages and pictures of grouped everyday objects. Presented on behalf of the territory, “Composing a Poem on Bamboo” was given by West Kowloon board member Ronald Arculli, who first spotted it at a charity silent auction in 2010.

Printed on rice paper, the artwork forms part of Mr. Hong’s “Elegant Gatherings” series, which reimagines Song and Ming dynasty masterpieces by featuring figures from the contemporary art world. The series is inspired by “Elegant Gathering in the Western Garden,” an 11th-century painting by Li Gonglin that portrays a conclave of literati. Mr. Sigg is pictured in the middle of Mr. Hong’s work, wearing a light blue shirt and standing behind a trio of ancient scholars.

Mr. Arculli, a former chairman of the Hong Kong Stock Exchange and long-time art lover, said he first came across the work at a fundraiser for Hong Kong-based nonprofit Asia Art Archive. “I felt it was special and though I had no occasion in mind, I thought I would buy it for Uli Sigg, who has always been a generous friend and patron,” he said.

He added that Mr. Sigg, who did not expect the gift and was visibly emotional, “thanked us very much.”

The artist, speaking through his Beijing gallery, Chambers Fine Art, explained that he created the work in 2007 by using photos he had snapped from various art gatherings. He then juxtaposed them with the classic Chinese image.

He identified the man to right of Mr. Sigg as Guangdong-born artist Chen Shaoxiong, who stands next to Tang Xin, director of Beijing gallery Taikang Space. To her right is artist Han Lei, who also often works in photography.

The two Westerners on the hill are strangers Mr. Hong photographed at an opening of the Asia Pacific Triennial of Contemporary Art in Queensland, Australia. The artist said he does not know their identity.