An artist’s larger-than-life digital image of a faceless male pedestrian, “Bruce Walking,” will stand on the steps of Tweed Courthouse until October, as an inadvertent but nonetheless striking symbol of the close ties between the exhibit’s sponsor, developer Bruce Ratner, and nearby City Hall.

In a move that raised eyebrows among citizens’ groups this week, Mayor Bloomberg instructed his four appointees on the Metropolitan Transportation Authority’s board to vote in favor of Mr. Ratner’s bid for control of the MTA-owned Vanderbilt Yard site in downtown Brooklyn. On Wednesday, the board authorized the MTA to enter into exclusive negotiations with Mr. Ratner’s firm over the sale of development rights at the 8.4-acre site, despite statements from board members appointed by Governor Pataki who complained that Mr. Ratner’s opening offer was “unacceptable.” Mr. Ratner, principal owner of the New Jersey Nets, wants to build an arena for the team as well as a highrise residential and commercial complex at the rail yard.

Mr. Ratner’s real estate firm, Forest City Ratner, is sponsoring the exhibit at Tweed, which is the headquarters of the Department of Education. A British painter and sculptor, Julian Opie, crafted the animated, orange light-emitting diode images of two figures: a male, “Bruce,” and a female, “Sara.” Asked this week if the exhibit’s title is linked to the developer’s first name, a Forest City Ratner spokesman, Joseph DePlasco, said: “We don’t comment on art.”

A spokeswoman for the nonprofit group that organized the display, the Public Art Fund, firmly denied any such link. And the diode Bruce’s physique, slender and lithe-looking, bears no resemblance to Mr. Ratner’s.

According to an e-mail that Mr. Opie sent to the art fund, the Bruce of “Bruce” is a professional dancer with the Ballet Rambert in London, who commissioned the artist to draw his portrait.

Mr. Opie does not have a record of the dancer’s last name, according to the artist’s studio manager, James Pidcock.

The only “Bruce” on Rambert’s list of cast members is the company’s former longtime artistic director, the dancer and choreographer Christopher Bruce. But Mr. Pidcock wrote in an e-mail that Mr. Bruce is definitely not the namesake of the diode image, because the mysterious dancer’s “first name is Bruce.”

Mr. Opie told the art fund that “Sara” is a fashion model with whom he has collaborated on several films. Mr. Opie used photographs of “Bruce” and “Sara” walking on a treadmill to produce the animated loop that has run continuously on the courthouse steps since last fall.

Even if “Bruce Walking” was not intended as a tribute to the eponymous developer, the president of the pro-Ratner group BUILD, James Caldwell, said Mr. Ratner deserves a monument to honor his commitment to delivering jobs and affordable housing to Brooklyn.

“He deserves all the accolades he can get,” Mr. Caldwell said.

Another Ratner ally, Bertha Lewis, executive director of the group ACORN, the Association of Community Organizations for Reform Now, agreed “something should be done to recognize” the developer for his cooperation with the borough’s black communities.

And Mr. Bloomberg, at a Brooklyn event last month, marveled at “how great this guy has been for Brooklyn and for New York City.”

A spokesman for the anti-Ratner group Develop Don’t Destroy, Daniel Goldstein, was less kind. He said it was fitting for “Bruce Walking” to be located at the steps of a building named for the notoriously corrupt 19th-century Tammany Hall leader William “Boss” Tweed. Both men, Mr. Goldstein charged, have benefited from “sweetheart backroom deals.”

In February, Messrs. Bloomberg and Pataki endorsed the Ratner project and pledged $200 million in direct subsidies for the developer, even though the MTA had not yet solicited competing bids for the rail yard site.

Even as the utility company Con Edison asked 81,000 city residents to eliminate unnecessary uses of electricity as a heat wave raised concerns of a blackout Wednesday, “Bruce” and “Sara” continued to walk nonstop on the courthouse steps. In response to an inquiry from The New York Sun, a spokesman for the Department of Citywide Administrative Services, Mark Daly, said there were no plans to unplug the display. He said the city does not track the amount of power that the exhibit consumes, but he added, “Light-emitting diodes were created for the purpose of using very little electricity.”