Amid the soaring ceilings and sparkling chandeliers of the Great Hall of the People, a high-stakes state banquet between Donald Trump and Xi Jinping provided a moment of unexpected ceremony in a subtle but strong sign of respect.

The meeting, which comes at a pivotal moment for US-China relations, was defined as much by what was left unsaid as by the formal toasts exchanged between the two world leaders.

Judi James, a noted body language expert, observed that Trump's entrance in the Great Hall signaled the gravity of the diplomatic mission. 

'Trump arrived beside Xi, with his heavyweight solemn walk suggesting a man with the weight and future of the world on his shoulders,' James said. 

She noted that while Xi appeared the more relaxed-looking of the pair - sporting a warm smile and asking Trump to admire the room - the American president remained guarded. 

'His expression remained stern rather than sociable and as he stood behind his seat at the table his posture looked rigid as he bounced up and down on his heels but his chin was raised to suggest high levels of pride.'

The evening was marked by subtle power plays and adjustments. 

Early in the dinner, Trump asked for a cushion on his chair to be removed, a move James suggested might have backfired as he then sat lower in his seat than a more upright Xi. 

However, as the Chinese president began his formal address, James noted that Trump suddenly appeared to 're-boot his sitting pose to something a little more dominant and alpha,' straightening from a slump to a dominant splay with one hand placed firmly on each knee.

The most striking moment of the night occurred during the exchange of toasts.

Trump took a swig of what appeared to be champagne during the state banquet.

Trump, who does not drink, has rarely been seen sipping alcohol, but took a small swig of the likely non-alcoholic beverage as a further sign of respect.

James says Trump's gesture was even more meaningful given the significant personal weight - adding that he accepted the glass and toast twice, without an 'fuss' or 'show of the act.'

The President has often recounted how his older brother's battle with alcoholism influenced his lifelong distaste for drinking. 

Fred Trump Jr. died young at 42 after suffering from a heart attack linked to complications from alcohol. 'Freddy,' as his family called him, was a commercial airline pilot before his drinking led to his inability to fly safely.

Trump has frequently called the sad story a formative moment for him, crediting his brother's advice as the reason he has never had alcohol, cigarettes, or drugs in his life.

Trump raised his glass to toast the 'rich and enduring ties between the American and Chinese people,' while Xi toasted the 'bright future of  relations.' 

It was the second time in a few weeks that Trump has been spotted making a toast with foreign keader, following a similar pattern in late April during a state visit from King Charles III.

As the banquet concluded and Xi returned to his seat, Trump stood to offer a final gesture of recognition. 

According to James, the President threw one hand out for an 'emphatic, hearty shake' while simultaneously grabbing Xi's bicep. 

James described the move as an 'alpha gesture of both recognition and respect for the other person's strength,' bookending a night of rigid protocol with a rare display of personal concession.