As the chief White House photographer for all 8 years of Obama’s presidency, taking intimate candid portraits of the president at work (and very, very occasionally at rest), Pete Souza has developed (photography pun!) some very solid ideas for how a president should behave.

Having also taken pictures of Reagan back in the day, Souza felt himself to be largely apolitical. He didn’t always agree with the decisions his subjects were making, but his job was to document their days, not comment on what he saw. And he never did. Top secret clearance and all that jazz.

As you can imagine, over the course of 8 years, with unprecedented access to the First Family, Souza has a bank of memories from his time with Barrack Obama, and he’s also got thousands upon thousands of photos. The two formed a friendship as close colleagues often will. Souza respected him as a man and admired him as a president.

But it wasn’t until Obama left office and you-know-who moved in that he truly started to consider how a president should behave. What a president should be seen doing. How the president’s image was a reflection of the country as a whole, and what damage it did not just to citizen morale but on the world stage as well, when a president continually insulted the very office they were elected to represent.

Pete Souza is not a politician. He’s not a public speaker or a talking head. He makes pictures, and those pictures quietly became his method of protest. Every time Trump would tweet something inane, and you know he’s spent nearly 4 years outdoing himself in the verbal diarrhea department, Souza would reply with a photograph of Obama looking dignified, personable, intelligent, presidential. He didn’t need to be any more pointed than that. The comparison was disheartening. And so over time, he has found a voice through his pictures, and a platform through Instagram. His followers call him the King of Shade, and after someone explained to him what throwing shade meant, he embraced the title and took the work even more seriously.

Dawn Porter’s documentary is a fun watch because of all the touching behind the scenes moments Souza shares with us. Obama’s absence has left a vacuum where gravitas and grace once belonged. Souza is filling that hole just a little bit. But more than that, his photos are a constant reminder of how a president can and should act.