It all began, as such stories often do, with a snarky tweet.I was headed to the headquarters of Sanofi Genzyme (NYSE: SNY) for an evening event last week when I spied it: A large, mysterious structure on the top of what is arguably the most iconic building in Kendall Square. It appears to be leftover scaffolding, something I’d noticed several times before atop the 12-story building. I’d always assumed it once held a sign reading “Genzyme” that the company had removed sometime in 2015, when it was announced it would be changing its name. But I also knew the building, completed in 2003, was kind of famous in architecture circles, winning the Harleston Parker Medal from the Boston Society of Architects in 2008 for being “the most beautiful building or other structure built in the greater Boston area during the past decade.”