Looks like others noticed the strange handshakes and overall strange behaviour too.
Trump's STRANGE & CODED Handshake with President of France
Trumps & Macron share some VERY weird handshakes and interactions! WHAT is going on here because this is not normal. Trump is talking in code here and is putting out a message to those who can decipher it. - In2ThinAir.
Related links: http://www.ephesians5-11.org/handshakes.htm
What Is A Masonic Handshake - Esoteric Freemasons