White House Press Secretary Sean Spicer was giddy at the thought of meeting Pope Francis during President Trump's first trip abroad, telling acquaintances that for him, a devout Catholic, the moment would fulfil a bucket-list dream.

But when the White House finalised the lucky list of staff members who would accompany Trump into his private audience with the pontiff at the Vatican last week, Spicer's name was nowhere to be found.

Enduring public humiliation has become a defining characteristic of Spicer's tenure in the White House - from the Saturday Night Live parody in which a woman plays a ranting, red-faced Spicer to the constant rumours of his imminent dismissal. Yet being excluded from the papal visit still stunned his colleagues, many of whom expressed pity for him and were visibly uncomfortable talking about the slight.

In Trump's White House, aides serve a president who demands absolute loyalty - but who does not always offer the same in return. Trump prefers a management style in which even compliments can come laced with a bite, and where enduring snubs and belittling jokes, even in public, is part of the job.

Allies say the President's quips are simply good-natured teasing, part of an inclusive strategy meant to make even mid-level staff members feel like family. But others consider Trump's comments pointed reminders to those who work for him that he is in charge - barbs from the boss that keep aides on guard and off kilter, and can corrode staff morale.

Trump sometimes refers to his 45-year-old chief of staff, Reince Priebus, as “Reince-y,” a diminutive nickname that some aides and outside rivals recount with gleeful relish. The president also frequently reminds Priebus that when Access Hollywood tapes emerged during the campaign on which Trump could be heard boasting about groping women without their consent, Priebus urged him to drop out of the race.

The president has described House Speaker Paul D. Ryan, Republican-Wisconsin, in theory one of his top allies on Capitol Hill, as a “Boy Scout” - a dig the that lawmaker joked he chose to take as a compliment even though “I'm not sure he meant it that way.”

And during the transition, Trump would make a point of noting that then-Vice President-elect Mike Pence's crowds paled compared to his, teasing that even his daughter Ivanka and son Eric attracted more attention, according to two people familiar with the comments, which they considered demeaning. (Pence offered a similar quip on the campaign trail.)

Even the president's family is not immune. In a news conference at Trump Tower shortly after he won the White House, Trump announced that he would be putting his companies into a trust that his two older sons would run during his presidency.

“I hope at the end of eight years, I'll come back and say, 'Oh, you did a good job,'” Trump said, as his sons looked on. But, then, he couldn't resist a final tweak - half joke, half warning: “Otherwise, if they do a bad job, I'll say, 'You're fired.'”

The White House says that Trump, who came of age professionally running a family business, is simply joking with his staff, part of a warm, familial leadership style that makes everyone feel included.

“President Trump has a magnetic personality and exudes positive energy, which is infectious to those around him,” Hope Hicks, Trump's communications director, said in a statement. “He has an unparalleled ability to communicate with people, whether he is speaking to a room of three or an arena of 30,000. He has built great relationships throughout his life and treats everyone with respect. He is brilliant with a great sense of humour... and an amazing ability to make people feel special and aspire to be more than even they thought possible.”

Many disagree with that assessment. Critics say the president often demeans those in his orbit, a tendency they say reflects a broader fragility beneath his bluster.

“Trump is so deeply insecure that not even becoming president of the United States quenched his need to make others feel small to build himself up,” said Tim Miller, a former spokesman for an anti-Trump super PAC. “Choosing to work for him necessitates a willingness to be demeaned in order to assuage his desire to feel like a big, important person.”

Trump's management style - whether good-natured ribbing or withering comments, depending on one's perspective - dates to his days as a Manhattan real estate developer, when Trump enjoyed operating in an environment of competing factions. Now, he has transplanted that executive philosophy into his White House.

When he decided to fire his FBI director, James B. Comey, the president did so in an especially humiliating way. Like a scene out of The Godfather, Trump first sent Keith Schiller, his former head of security, to deliver the message to Comey at FBI headquarters. His allies maintain that Trump simply wanted the job done well, so he dispatched Schiller, whom he trusts deeply, in a sign of respect for how seriously he took the moment.

But Comey, who was across the country visiting a Los Angeles field office, ultimately found out in embarrassing fashion - in public, from television, in full view of his staff. As Comey was delivering a speech to FBI field employees, he initially laughed as news flashed across the TV screens that he had been fired. “How'd you guys do that?” he asked, according to someone briefed on the moment.

The FBI director assumed he was being pranked by his underlings - and had to be told by his team that the headlines were no joke. He had been dismissed, effective immediately.

During a February prayer breakfast in Washington, Mark Burnett, the creator of The Apprentice, introduced Trump, who went on to make a few tone-deaf jokes about Arnold Schwarzenegger, who had replaced him as the show's host.

“The ratings went down the tubes,” the president said. “It's been a total disaster and Mark will never, ever bet against Trump again. And I want to just pray for Arnold if we can, for those ratings, OK?”

Trump's friends and allies reject the notion that he diminishes those around him, saying the businessman-turned-president is simply trying to bring out the best in his employees.

“I think it's more New York swagger than he's trying to belittle them,” said Christopher Ruddy, the chief executive of Newsmax, a conservative media company, and a longtime friend of Trump's. “I always say he makes people feel like a million bucks.”

The approach, however, frequently leaves Trump's top team open to some of his more cutting digs.

At a private dinner shortly before he was inaugurated, Trump took aim at his incoming vice president and his incoming secretary of state, Rex Tillerson.

Complimenting his vice presidential choice, Trump also reminded the crowd - and Pence - that he could have just as easily chosen someone else. “Oh, I had a couple of beauties I could have picked,” Trump said. “They were good, too, but maybe they wouldn't have worked out like Mike.”

Turning his attention to his secretary of state pick at the same gathering, he hinted that Tillerson - a former chief executive of ExxonMobil - might be in for a steep learning curve in the Trump administration. “Where's our Rex?” Trump asked. “Wow. What a job. Thank you very much, thanks Rex. I think it's tougher than he thought. He's led this charmed life. He goes into a country, takes the oil, goes into another country. It's tough dealing with these politicians, right?”

Trump also sometimes reminds even his senior advisers, in ways big and small, that he has the power to demote them at any time. During an Oval Office meeting about trouble spots abroad, a relatively junior foreign policy staff member prepared to take a seat on the periphery as the president's top aides, including chief strategist Stephen K. Bannon, surrounded him in chairs around the Resolute Desk. But the president soon ordered up a change, said someone who witnessed the moment, telling Bannon to give up his seat for the junior staff member and relegating his top strategist to the couch.

More recently, during a lunch with ambassadors from countries on the UN Security Council, Trump jokingly polled those in the room on whether they thought UN Ambassador Nikki Haley, seated directly to his right, was doing a good job.

“How do you all like Nikki?” he asked, as Haley looked on. “Otherwise, she can easily be replaced.”

Close foreign allies are also targets of Trump's public and private dressing-downs.

During an early call with Australia, one of nation's staunchest allies, the president got into a testy exchange with Prime Minister Malcolm Turnbull, blasting him over a refugee deal, bragging about the size of his electoral college win and abruptly ending the call.

When news from the conversation emerged, Trump's team readily confirmed details of the exchange. The president was livid about the leak - but had no problem being viewed as a bully, believing he was simply standing up for his nation's best interests.

The pattern continued in his trip overseas last week, when he gushed about the autocratic Saudi royal family even while insulting European allies. At a stop in Brussels, the president chastised Nato members for not meeting their financial responsibilities, shoved aside a Balkan prime minister to get in front for a group photo and needled his allies about the price tag on a new building for the alliance.

Donald Trump's first 100 days: in cartoons Show all 33 1 /33 Donald Trump's first 100 days: in cartoons Donald Trump's first 100 days: in cartoons Donald Trump's first 100 days in office were marred by a string of scandals, many of which caught the eye of the Independent's cartoonists Donald Trump's first 100 days: in cartoons Trump's first 100 days have seen him aggressively ramp up tensions with his nuclear rivals in North Korea Donald Trump's first 100 days: in cartoons Mr Trump has warned of a "major, major conflict" with the pariah nation lead by Kim Jong Un Donald Trump's first 100 days: in cartoons Mr Trump dropped the "mother of all bombs" on alleged ISIS-linked militants in Afghanistan, amid an escalation of US military intervention around the globe Donald Trump's first 100 days: in cartoons Mr Trump has been accused of falling short of the standards set by his predecessors in the Oval Office, including Franklin D Roosevelt Donald Trump's first 100 days: in cartoons The tycoon's ascension to the White House came at a time when the balance of power is shifting away from Western nations like those in the G7 group Donald Trump's first 100 days: in cartoons Western politicians, including the British Conservative party, have been accused of falling in line behind Mr Trump's proposals Donald Trump's first 100 days: in cartoons Brexit is seen to have weakened Britain, reducing still further any political will to resist American leadership Donald Trump's first 100 days: in cartoons Mr Trump's leadership has been marked by sudden and unexpected shifts in global policy Donald Trump's first 100 days: in cartoons Trump's controversial missile strike on Syria, which killed several citizens, was seen by some analysts as an attempt to distract from his policy elsewhere Donald Trump's first 100 days: in cartoons The President has also spent a large majority of his weekends golfing, rather than attending to matters of state Donald Trump's first 100 days: in cartoons Though free of gaffes, a visit from Chinese president Xi Jinping spotlighted trade tensions between the two states Donald Trump's first 100 days: in cartoons One major and unexpected setback came when Mr Trump's Healthcare Bill was struck down by members of his own party Donald Trump's first 100 days: in cartoons Mr Trump has been a figure of fun in the media, with his approval at record lows Donald Trump's first 100 days: in cartoons A string of revelations about Mr Trump's financial indiscretions did not mar his surge to the White House Donald Trump's first 100 days: in cartoons Outgoing President Barack Obama was accused of wiretapping Trump Tower by his successor in America's highest office Donald Trump's first 100 days: in cartoons The alleged involvement of Russian intelligence operatives in securing Mr Trump the presidency prompted harsh criticism Donald Trump's first 100 days: in cartoons The explosive resignation of Security Adviser Michael Flynn, who lied about his links to the Russian ambassador, was just one scandal to hit the President Donald Trump's first 100 days: in cartoons Many scandals, such as the accusation Barack Obama was implicated in phone-hacking, first broke on Mr Trump's Twitter feed Donald Trump's first 100 days: in cartoons Donald Trump's election provoked mass protests in the UK, with millions signing a petition to ban him from the country Donald Trump's first 100 days: in cartoons Donald Trump cited a non-existent terror attack in Sweden during a campaign rally Donald Trump's first 100 days: in cartoons Donald Trump stands accused of stoking regional tensions in Eastern Asia Donald Trump's first 100 days: in cartoons North Korea has launched a number of failed nuclear tests since Mr Trump took power Donald Trump's first 100 days: in cartoons Theresa May formally rejected the petition calling for Mr Trump to be banned from the UK Donald Trump's first 100 days: in cartoons When Mr Trump's initial so-called Muslim ban was struck down by a federal justice, the President mocked the 69-year-old as a "ridiculous", "so-called judge" Donald Trump's first 100 days: in cartoons A week after his inauguration, Theresa May met with Mr Trump at the White House Donald Trump's first 100 days: in cartoons Donald Trump's first days in office were marked by a hasty attempt to follow through on many of his campaign promises, including the so-called Muslim ban Donald Trump's first 100 days: in cartoons Donald Trump's decision to ban citizens of many majority-Muslim countries from the US sparked mass protests Donald Trump's first 100 days: in cartoons Revelations about Donald Trump's sexual improprieties were not enough to keep him from being elected President Donald Trump's first 100 days: in cartoons British PM Theresa May was criticised by many in the press for cosying up to the new President Donald Trump's first 100 days: in cartoons One of Mr Trump's top aides, Kelly Anne Conway, was mocked for describing mistruths as "alternative facts" Donald Trump's first 100 days: in cartoons British PM Theresa May was quick to demonstrate that her political aims did not hugely differ from Mr Trump's Donald Trump's first 100 days: in cartoons Donald Trump's inauguration, on 20 January 2017, sparked protests both at home and abroad

During his first in-person meeting with French President Emmanuel Macron, Trump's typically aggressive greeting became a duel of oneupmanship as the two men clenched their jaws and tightened their faces during an intense, white-knuckled handshake.

Macron, France's newly elected 39-year-old leader, later said he wanted to show Trump that he would not be pushed around or demeaned.

“I don't believe in diplomacy by public abuse,” he said.