Washington CNN  — 

Former presidential photographer Pete Souza can’t stop, and won’t stop, throwing shade at the Trump administration.

“SHADE: A Tale of Two Presidents” will be published in October, Souza announced Wednesday in an Instagram post.

Since the end of the Obama administration, Souza, who photographed Presidents Barack Obama, a Democrat, and Ronald Reagan, a Republican, has frequently taken to his Instagram account to post images in response to President Donald Trump’s actions and policies. While some of the images were subtle critiques, Souza, who hadn’t previously been seen as a partisan figure, soon became known for visually trolling the Trump administration, which, he said Wednesday, “has become a reality game show.”

“I do this not as a partisan hack, but as an American citizen concerned about the future of our democracy because of our current president,” Souza posted on Instagram. “My commentary on Instagram has been subtle, sometimes humorous, and certainly more respectful than his commentary on Twitter.”

He kept it up.

When Trump prepared to unveil Supreme Court nominee Neil Gorsuch in January 2017, Souza posted an image of Obama and Vice President Joe Biden alongside a smiling then-nominee Merrick Garland.

“Merrick Garland. Just saying,” he captioned.

Shortly after Trump fired FBI Director James Comey in May 2017, Souza posted an image featuring Obama and Comey, among others, in the Oval Office.

“Every person in this photograph is a patriot,” he said.

This February, Souza quoted a favorite phrase of Trump’s alongside a photo of Obama greeting a White House trick-or-treater dressed up like the Wicked Witch of the West.

“WITCH HUNT!” he wrote.

Last week, he posted an image of pup Bo Obama sitting in the President’s chair at the Resolute Desk in the Oval Office.

“Bo never leaked in the Oval Office. Believe me,” he said.

Souza admittedly did not know what it meant to “throw shade” when he began the posts, which quickly went viral. But he “soon learned he was doing it,” his publisher said in a news release.

The photographer and author promised that his new collection of images will reflect on the past, saying, “SHADE will vividly show where we are as a country contrasted with where we were.”

The publisher describes the forthcoming book as “More than a sharp compendium of ‘claps back.’ “

Souza’s first book, “Obama: An Intimate Portrait,” was a best-seller in 2017, and he’s since toured the country giving speeches.

CNN’s Sophie Tatum contributed to this report.