Nic Robertson is CNN's international diplomatic editor. The opinions in this article belong to the author.

A senior member of the Saudi royal family recently told me that word around the royal palaces is that President Trump pays attention when business is in the offing.

The full impact of what he meant has only just started to sink in.

Certainly it was clear last May during Trump's inaugural overseas trip to Riyadh , where he proudly announced huge arms deals worth more than $100 billion.

The message was clear: a boon for the US economy and the President delivering on his campaign promise to bring jobs to America.

His communications team said there would be tens of thousands of jobs created, thanks to the signatures Trump was collecting from the Saudi leadership.

This week, Saudi Arabia's leader-in-waiting, Crown Prince Mohammed bin Salman, paid Trump a return visit, with the President once again reeling off the list of deals they're doing.

Sitting side by side with the Crown Prince in the Oval Office, Trump wielded a huge check.

"$3 billion ... $533 million ... $525 million ... that's peanuts for you," he said looking at MBS.

The Crown Prince was grinning and shaking his head. Trump continued: "$880 million ... $645 million ... $6 billion ... that's for frigates."

By the time Trump got to HIS second card, MBS was looking quite uncomfortable.

Trump continued reeling off a laundry list of arms sales, claiming that all these deals meant "over 40,000 jobs," before tantalizingly touting deals next worth $700 billion next year.

Later, a source with knowledge of the meeting told me MBS felt humiliated by Trump.

MBS, he said, wasn't expecting to have the huge cards, detailing billions of dollars of business deals dangled under his nose. It's not the publicity he came to Washington to get.

His public DC pitch is all about how he is changing Saudi Arabia, turning it into a more palatable ally, reforming Saudi society for the better, empowering women, employing the country's youth, making it an easier place to do business and weaning it off hydrocarbons.

His visit to London two weeks ago was a trial run for his DC trip. According to a source familiar with the trip, about $1.4 million was spent on advertisements, on billboards in London, proclaiming "He [MBS] is opening Saudi Arabia to the world."

The message: at 32 MBS is young and in a hurry.

Saudi officials I've met who work with him describe him as a human dynamo, consuming spreadsheets and Powerpoints, spitting facts and figures, setting a high bar for everyone in his employment and expecting results pronto.

On his DC agenda is thrusting Saudi out of hydrocarbon dependency and fast-forwarding it to a nuclear-powered future. He wants US nuclear power plants and a generation of engineers and technicians educated to run them.

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It is part of his much-hyped 2030 vision for the renewal of the desert Kingdom.

However, his public relations blitz in London and DC is not sticking the way he might hope. He is dogged, not just by Saudi's past, but also by its present.

Questions asked in the UK Parliament highlighted how far he still has to go to clean Saudi's image.

Opposition MP's questioned whether the government should be hosting MBS, considering his and Saudi Arabia's role in the war in Yemen.

So to have Trump reel off the latest additions to the desert Kingdom's weapons arsenal is to annihilate MBS's carefully curated narrative of a country under change for good, instead casting him as an old-style leader, capable of flexing his military muscle.

But there are a raft of other reasons MBS isn't shedding Saudi's old image of a cultural backwater, typified by a society stuck in outdated attitudes and practices governed by mega-rich princes.

His recent corruption crackdown, jailing royals and business leaders in Riyadh's Ritz-Carlton hotel, is the most glaring.

Officials say the exercise stuffed the Saudi coffers with about $100 billion of looted state monies, but nevertheless, it was widely interpreted as MBS consolidating power.

The sudden incarcerations -- which included the unexplained death of one detainee -- unnerved potential investors, the very people the shiny, new Saudi image is supposed to entice.

After he is done in DC, MBS will go on a week-long US tour, meeting business leaders trying to put the sparkle back on the high-priced PR sheen he's paid for.

But before he leaves the nation's capital and the world's most powerful man, there will be one conversation he is sure to have with Trump: what to do about Iran.

Beyond doubt, MBS and most Saudis like Trump's anti-Iranian rhetoric. For them, he is an American President who is much more in tune with their interests than President Obama was.

Both leaders read Iran's actions in Iraq, Syria, Lebanon, Yemen and beyond as a threat to regional stability. Both have talked openly about curbing Iran's growing military clout.

Trump's dislike for the Obama-era nuclear deal with Iran aligns neatly with MBS's views.

In a recent interview with CBS' "60 Minutes," MBS said that if Iran develops a nuclear weapon, Saudi Arabia will want one too.

His brother, Khalid bin Salman, his Ambassador to DC, had this on-air conversation with Wolf Blitzer earlier in the week, raising questions about what Saudi may do with the nuclear technology it wants.

Salman: "We think the deal [JCPOA] needs to be fixed. We are on autopilot headed toward a mountain. We need to fix the deal now, not to face the consequences later."

Blitzer: "The Crown Prince says Saudi Arabia doesn't want to develop nuclear weapons, but it would if the Iranians achieved that. Explain your position on that."

Salman: "We'll do whatever it takes to protect our citizens, our people and our country. "

MBS and his brother may be getting closer to what they want on Iran. This week Trump fired his Secretary of State, who had become a brake on the President's impulse to exit the Iran deal.

But a new wrinkle in the Saudi-US relationship could be emerging, one that if true could dent MBS's desire for an image makeover more than Yemen, more perhaps even than 9/11.

If true it would be illegal, and so far the White House has yet to comment.

It's caused me to reconsider precisely what the senior Saudi royal meant when he told me about their read of Trump. Did he really mean that in Trump, they saw a President willing to barter US foreign policy for a few bucks -- potentially at the cost of US national security interests?