The traditional mug shot is usually a grim affair: poorly lit and sullen. It is a permanent portrait of shame — the legal system’s scarlet letter.

It is, almost by definition, unsmiling.

But the booking photos emerging from the Fulton County Sheriff’s Office in Atlanta, where Donald J. Trump and 18 others are being charged with conspiring to overturn the 2020 election, include several that are oddly cheerful.

Mr. Trump’s former lawyer Jenna Ellis smiles broadly, as does David Shafer, the former chairman of the Georgia Republican Party. Scott Hall, a Trump operative, fails to repress a smirk. Sidney Powell, accused of peddling debunked conspiracy theories about the election, reveals a twinkle in her eye.

The statement that all of their facial expressions convey unmistakably? Defiance.

How Mr. Trump will approach his fateful appointment with a sheriff’s photographer when he posts bail Thursday night is anyone’s guess — although he has long favored a scowl over a grin, the better to project strength.

But the way his accused co-conspirators have been composing themselves for the camera of the criminal justice system, and for the lens of history, evokes the other supporting roles they are playing, in what seems an extraordinary production of political theater — one in keeping with Mr. Trump’s oft-repeated contention that the prosecution is a farce and a joke.

In Ms. Ellis’s all-smiles mug shot, taken on Wednesday — so cheerful it could be a profile pic, but for the sheriff’s office logo over her shoulder — she appears just shy of laughing at the hilarity of where she finds herself.

Modern politics in the age of social media is, as much as anything, a battle to create, control and define visual images. And the mug shot, pioneered in 1840s Belgium as a utilitarian method of identification, is becoming a new front in that fight.

Most other defendants booked so far on charges of conspiring to overturn the 2020 election betrayed their grave predicament, none more so than Rudolph W. Giuliani, who pursed his lips, stared icily ahead and grimaced after surrendering on Wednesday in Atlanta. Ms. Ellis, who has portrayed her indictment as an unfair political persecution to be overcome through faith and positivity, tried to take ownership of a process more often seen as intimidating or humiliating.

She posted her mug shot online, with an empowering quote from Psalms: “Shout for joy, all you who are upright in heart.”

Ms. Ellis, responding to a request for comment, compared her predicament to that of a former law client, a minister who defied an order to close his church during the pandemic.

“Those who mock me, my former client, and my God want to see me break and they aren’t going to get that satisfaction,” she said. “I smiled because I am resolved to meet this process with courage and acting in faith. They cannot steal my joy.”

Ms. Powell and lawyers representing Mr. Shafer and Mr. Hall did not immediately respond to requests for comment. Having a Fulton County mug shot may even become a marker of status among Mr. Trump’s most die-hard supporters: Amy Kremer, who helped organize the rally that preceded the Jan. 6, 2021, riot at the Capitol, posted a doctored photo of herself — unsmiling — in front of the Fulton County Sheriff’s sign, though she has not been charged in Georgia.

The mug shot is supposed to be a leveler, subjecting the mighty and the powerless to the same objective lens. And many Trump enemies have criticized the U.S. Marshals Service for declining to take mug shots, as they would with other defendants, when the former president was booked on federal charges in Miami and Washington.

This time will be different.

Politicians, as a general rule, have approached their bookings as political events that will ultimately influence the legal outcome.

When Tom DeLay, the House majority leader, was accused of money laundering and conspiracy charges in 2005, he donned his suit, tightened his tie and smiled from ear to ear, cannily depriving his opponents of an image they could easily use in attack ads against him. (He left Congress, but his subsequent conviction was overturned on appeal.)

John Edwards, the former North Carolina senator and 2004 Democratic vice-presidential candidate, smiled as warmly for the camera as if he were greeting a political supporter when he was booked on charges of violating campaign finance laws in 2011. Like Ms. Ellis, he sought to convey his innocence and the unfairness of the charges. (He was acquitted on one charge, and the government dropped the remaining counts.)

And in 2014, Rick Perry, then the Republican governor of Texas, offered a sly grin during his booking on charges that he had pressured the Democratic district attorney of Travis County to resign. He called the charges “a farce,” posted pictures of himself at an ice cream shop shortly after and was cleared of all charges two years later.

More often than not, a mug-shot smile has been a token of defiance.

That has been particularly true for celebrity criminals who have, in general, been nearly as attentive to their images as movie stars or politicians: Al Capone smiled in several mug shots and for his identification photo at Alcatraz. And in the sole mug shot ever taken of the drug lord Pablo Escobar, after he was arrested on drug charges in Colombia, he seemed nearly jubilant.

He had good reason. The charges were quickly dropped.