"That's what leadership's all about," the New Yorker told reporters after the two men shared a half-hour conversation over coffee. "You can't be flexible and lead."
Nutter's dance card in the big city included conversations with top city officials about economic development, social welfare, information technology, and, of course, fighting crime.
At a late-afternoon meeting, Police Commissioner Ray Kelly didn't give the Democratic nominee any precise prescription for how to reduce Philadelphia's homicide rate, which is about five times New York's on a per capita basis.
But he did talk about what he thought was working here.
New York takes two-thirds of every new crop of officers coming out of its police academy and uses them to flood zones high in violent crime. The department also makes widespread use of the tactic of stop, question and frisk - to perform weapons searches on suspicious people.
"By and large, I think the tactic has been helpful in reducing the number of guns and the amount of violence on the street," Kelly said after his closed meeting with Nutter. "It does have the potential of creating friction. If you're stopped and you didn't commit a crime, you're not too happy about that."
Nutter, who took considerable heat during the spring mayoral primary for advocating the tactic, came away reinforced in his belief that this approach could help if done right.
And he told Kelly that he'd welcome input - after the November election - about candidates for Philadelphia's next police commissioner.
"The crime numbers in New York speak for themselves," Nutter said. "What I see is a relentless pursuit to drive down the numbers, to create a [good] quality of life."
Throughout the day, as he toured various city offices, Nutter was struck by the number of young people in places of authority, which is a real contrast to Philadelphia.
For instance, the first stop of the day was New York's vast 311 center, 311 being a 911-style telephone number through which local residents can obtain access to city services and all manner of basic information.
The tour was conducted most prominently by Elizabeth Leath, the system's analyst for community affairs. Leath is 25. She's been working on 311 for five years. She started as a college intern.
Nutter said that he wanted both a 311 system and a way to get talented young people involved in city government.
The candidate also took a tour of Bloomberg's City Hall "bullpen."
In that one large room, Bloomberg has his desk at the center, surrounded by his top aides and deputies. There are no offices, only cubicles with very low walls.
Nutter wasn't ready to declare that he'd recreate the bullpen in Philadelphia. But he wasn't ready to rule it out, either.
"I've thought about it - where, how, all of those issues," he said. "Reading about it is one thing. Having seen it, I'm thinking about it that much more. And I'm thinking about whether and how to restructure Philadelphia's government."
The visit here was Nutter's third field trip of the summer, following excursions to Baltimore and Chicago. In each case, he's been looking for practices he might want to implement should he defeat Republican Al Taubenberger this fall and succeed Mayor Street in January.
"There's a lot to learn here and in the other cities," Nutter said, calling his trips valuable. "We in Philadelphia have to stop being so parochial about ideas and strategies. . . . It is about getting things done."
He also got a taste of what it's like to be mayor of New York.
During a late-morning news conference with Nutter, Bloomberg was asked whether the city should ban underwear-revealing, low-riding pants and about hotel magnate Leona Helmsley's will, in which she bequeathed $12 million to her dog.
At the same event, Bloomberg said he was welcoming Nutter even though the Phillies had won three straight from the Mets, saying the Mets were only trying to make things interesting "before we pull away" in September.
That, of course, was before the Phillies beat the New Yorkers one more time.
Contact senior writer Larry Eichel at 215-854-2415 or email@example.com.