There he is in the backseat of the papal Fiat. There he is photobombing the pope and President Obama again and again like it’s his job (which it kind of is). When Francis walked into House Speaker John Boehner’s office Thursday, a vision in white, the pope’s interpreter was to his left, a step back, in black, like a shadow.

“Really glad that you’re here,” said Boehner, becoming the first speaker of the House to welcome a pope to Congress.

“I’m pleased to be here, thank you,” the interpreter said, masked from the cameras by the pope but speaking for him at that historic moment.

The interpreter is Monsignor Mark Miles, and details about him are scarce. He declines interviews. When he speaks, it is to translate. What we know: He is a native of Gibraltar and, according to social media, he is cute.

It’s something about his eyebrows, or his glasses, or the fact that he appears to be a whole head shorter than the 78-year-old pontiff (though that may be just a posture issue, since he’s always leaning into the conversation). It might be the way he moves his hands like a conductor, how he gestures to the people he’s interpreting, and how the pope often responds with his own gestures, so that the pair seems on always on the verge of a low five, or a secret handshake, or patty-cake. It might be Miles’s British-like accent, dulcet and clean whereas the pope’s English is halting and gooey.

“I don’t have an ear for it,” Francis once told a biographer, referring to English as his greatest linguistic challenge.

That’s where Miles comes in. When the pope addressed the crowds outside the Capitol Thursday morning, Miles was behind him at a microphone, like the Wizard of Oz. When the pope mounted his popemobile on Fifth Avenue in New York Thursday afternoon, Miles was in the jump seat. The media have taken to calling Miles the pope’s wingman, but at least one fan has a more dignified designation:

Miles works in the English section of the Vatican’s Secretariat of State and he’s a native Spanish speaker. That alignment might explain his relative prominence in this papacy, according to the Rev. John Wauck, an American priest and communications professor at the Pontifical University of the Holy Cross in Rome.

“This pope likes to speak off the cuff, even in places where few will understand his Spanish or Italian,” Wauck said via e-mail. “In order to render those spontaneous remarks intelligible, a very good simultaneous translator is necessary, and he couldn’t have asked for a better one than Msgr. Miles.”

Pope Francis visits Our Lady Queen of Angels School in East Harlem during his six-day U.S. visit. (Reuters)