A psychologist specializing in body language has analyzed visible cues between President Donald Trump and his assistant Natalie Harp, saying the pair appear to have a "strange dynamic."

Dr. John Paul Garrison, a clinical and forensic psychologist, has published numerous videos using his expertise to examine Trump's body language and well-being. While many of his recent videos have focused on signs of neurological decline, his latest video examined Trump's relationship with Harp, the young assistant whose loyalty to the president has been described by many as obsessive.

Harp first entered Trump's orbit during the years he was away from the White House. Since his return, she has become one of his closest assistants, carrying a portable printer with her at all times so she can share flattering reports and information with him. She also holds significant influence over the information he sees, a role that helps explain why her proximity has drawn attention well beyond typical staff relationships. Her devotion has alarmed staffers and Secret Service members, who have raised concerns that her behavior could become a security risk.

In his latest video, Garrison examined recent footage in which Harp stood near Trump as he delivered an address.

"One thing you may notice is that Natalie Harp is constantly smiling," Garrison said. "Now, you've only watched her for a few seconds, but you're going to see the same facial expression throughout the rest of this, as well as other video clips of her. She is always smiling. So, why is that? Why is it that President Trump would need somebody that is constantly smiling? Primarily because he's looking for constant admiration. He's looking for immediate feedback to say, 'You're doing great. Everything you do is great.' And keeping a facial expression like this, keeping this smile all the time, helps him [get] that."

He added, "And I don't want people to think I'm being critical that she is smiling. That's really not what I'm saying. But the point is that he doesn't care about authenticity. He doesn't want genuineness. What he wants is unusual amounts of loyalty. He wants devotion. He wants admiration. And so having somebody that keeps this look all the time is going to help feed that for him."

Garrison also pointed to a moment in the clip when Trump noticed Harp standing nearby and then began looking back at her more often. He said that was likely because she "truly is a source of comfort for him." Trump did not appear to show a different expression when he looked at her, which Garrison said reflected the way Trump views such people.

"People like this are objects," he said. "They are to be used. So when he looks back at her, it may provide him security, but he's not going to feel the need to smile or nod or give any sort of recognition because he doesn't see it as a two-way street like that."

Garrison said Trump continued looking back at Harp throughout the clip, reinforcing the sense that her presence was somehow "regulating" for him. He also noted that her smile appeared to grow when Trump tried to make a joke, and that she was "constantly" nodding in affirmation even when he was not looking at her. Another woman standing beside Trump in the clip was also nodding frequently, but Garrison said that was normal because she was part of the conversation, while Harp seemed to be "just so used to reaffirming everything that he says."

"It seems like almost by default she's constantly nodding her head along with every single statement he makes," Garrison added.

He later contrasted Harp's behavior with that of First Lady Melania Trump, using footage of her alongside her husband at the Freedom 250 race in Washington, D.C., where she appeared "disengaged" from him, often looking away and keeping her hands in her pockets.

"Melania Trump, on the other hand, is a lot more aloof," he said. "She seems to resist physical touch from him. She seems to move away. She seems to show that she's quite irritated with him at times. And obviously, the dynamic is different. But I thought it would be interesting to contrast the two of them because the response that he's going to get is going to be so dramatically different. And Trump may actually be somewhat psychologically reliant on Harp at this point because of that constant sense of admiration."