The mainstream publication talks about Putin's "pure machismo" meeting Trump's habit of making "his every handshake with a world leader into a test of both symbolic and physical strength".
One person was arrested and a passerby, who was not involved in the demonstration, was slightly injured, according to a police message on Twitter.
The G20 countries account for more than four-fifths of gross world product and three-quarters of global trade, and are home to almost two-thirds of the world's population.
It is understood a working draft of the communique includes a climate action plan with room for clean coal if G20 members so desire.
Signing up to an anti-protectionist pledge used to be routine at G20 meetings, but not this time.
Trump will look to a public speech on Thursday to burnish his credentials as a global statesman and deflect allegations that he has invited ridicule on the United States. Do you think it is Trump's fault, or Angela Merkel's fault?
With the on-going stand-off at the Sikkim section of the border, analysts say a meeting at the highest level could help deescalate the situation, as was the case in previous instances most notably during Xi's September 2014 visit to India amid a stand-off in Chumar in the western sector.
"It is, for example, open whether we can and should in the future rely on the U.S. investing so much as it has so far in the United Nations' work, in Middle East policy, in European security policy or in peace missions in Africa", Merkel was quoted as saying. The demonstrators also urged the G20 leaders to "fight poverty" and "put an end to the coal industry".
He "also underscored his appreciation for Italy's efforts to address the significant Libyan migration crisis", according to the White House statement.
Some other banners read "Planet Earth first!" in what appears to be a reference to US President Donald Trump's political slogan "America First!". The German DAX and France's CAC 40 index dropped around 0.7 percent each while the U.K.'s FTSE 100 shed half a percent.
The police made use of tear gas and detained a person, she said.
Forty-seven percent of those between the ages of 18 and 24 said they would choose Merkel over the Social Democrat's candidate, Martin Schultz, for Germany's highest executive office.