Wait, did Marty Walsh just tease a Don Chiofaro harbor tower?

An image of a long-planned, but never formally-proposed, skyscraper that developer Don Chiofaro wants to build on the downtown Boston waterfront popped up in a presentation given by Mayor Martin J. Walsh this week.Boston Planning & Development Agency

Eagle-eyed observers of Mayor Martin J. Walsh’s Wednesday speech on climate change at a Greater Boston Chamber of Commerce breakfast may have noticed in his PowerPoint presentation something they’ve never before seen: the skyscraper that developer Don Chiofaro wants to build on the site of the Boston Harbor Garage.

But there it is, included in a few slides about proposed improvements to the downtown waterfront — the image of a sculpted tower soaring 600 feet above Central Wharf and the New England Aquarium. The kind of building that would make quite a mark on the downtown skyline.

It has been years since Chiofaro shared any images of what his long-delayed tower might look like, even amid seemingly endless debate about its height and mass. The closest he has come to a reveal was in June, when he released an image of a plaza below it — his take on the Aquarium’s “Blueway” open space. In it, just a slice of the tower’s lower floors are visible. At the time, Chiofaro said more images, and a formal proposal, would come by the end of summer. That’s yet to happen.

So when Chiofaro’s tower popped up in Walsh’s presentation, it attracted attention. Many developers run ideas past City Hall before airing for public consumption. Perhaps Chiofaro had shared his tower with the Boston Planning & Development Agency, and it wound up in a slideshow. Was this the tower design we’ve been waiting to see?

Developer Don Chiofaro. John Tlumack

Alas, no.

It’s just theoretical, based on what’s allowed on the site under its new zoning, said BPDA spokeswoman Bonnie McGilpin. BPDA staffers inserted the image, sculpting and all, to give a sense of what might come. But it’s just a rough sketch.

“The images are supposed to be what the future will look like,” McGilpin said, noting that they include other planned, but not-yet-permitted, projects at Suffolk Downs and in South Boston.

Yes, but none of those have spawned years of controversy dating to the previous mayoral administration. None have triggered lawsuits against the state. And none would transform for decades to come postcards that depict Boston’s waterfront.

Apparently, we’ll just have to keep waiting to see what all that fuss has been about.