The prep took place in Westchester County, New York, two days ahead of the first presidential debate.
He attached a low-quality video of Clinton and him practicing introductions for the debate, where he walked up to her and tried to hug her while she jokingly ran away.
Soft applause can be heard in the background as Clinton makes her way towards the Trump stand-in, waving to the nonexistent crowd.
Longtime Hillary Clinton aide Philippe Reines on Friday shared a video of himself nearly violently hugging his boss, showing how Clinton's campaign had prepared the then-presidential candidate for Donald Trump's notoriously forceful handshakes.
Comey, who Wittes said "stood in the back, right in front of the drapes, hoping Trump wouldn't notice him camouflaged against the wall", went to shake Trump's hand. But it didn't work - Trump called him out by name, leading to a greeting captured on camera.
Philippe Reins, a political consultant who once served as a senior adviser to Hillary Clinton during her tenure as secretary of state, has posted a video showing how Clinton worked to avoid unwanted Trump hugs during her debate preparations. It was bad enough there was going to be a handshake.
The Frankenstein-like approach to a hug seems eerily accurate, though "Trump's" chasing after Clinton after being awkwardly denied was probably hyperbole.
CORRECTION: This story was updated to reflect that the handshake between Trump and Comey occurred in the Blue Room of the White House.