That was the ultimate horse head on the pillow in my opinion. It's odd that so little is said about that. Instead it was covered as if it were some kind of fraternity prank, like: "Wow, those Russian PR people sure got the jump on the Americans in getting their news spin out there first. They had their photos online before we even confirmed who was at the meeting ". Yeah, sure they did, but it wasn't about them making sure that the story got framed the way that they wanted to the larger world. It was a warning to Donald Trump.
The day after Trump fired Comey, Putin called in that promise he got from Trump to meet with Foreign Minister Lavrov in the Oval Office. That by itself can be called subtle, even normal in a way. That Ambassador Kislyak was also present again by itself was not that odd. But in the context of a meeting between a Foreign Minister and a Head of State, the local Ambassador in essence functions as an aid, a high level staffer more senior than the translator in the room, but still not central to the theatrics of the event.
But in this case that Ambassador is a central figure to the FBI Russia investigation, the investigation that had been led by the man our President fired the day before. Ambassador Kislyak was central to the National Security Advisor of the United States getting compromised and fired. He was central to the U.S. Attorney General being forced to recuse himself (supposedly) from any FBI Investigation of the Trump campaign. Why on Earth did Donald Trump pose for a solo closeup photo with Kislyak shaking hands and grinning from ear to ear, while the American press pool was locked outside the door? Stupidity? Naivety? Genuine affection? Blackmail?
Whatever. What's far more interesting to me though is why the Russians made sure the whole world saw that photo on a day when the Trump team was still trying to argue that Comey's dismissal had absolutely nothing to do with Russia. A coincidence perhaps, or a failure on the Russian's part to grasp the U.S. news cycles? Uh huh. About as likely as ten years worth of Trump tax returns still remaining under IRS audit.
Putin sent Trump a message; "You know that photo we had of you that you really didn't want or expect the world to see? How do you like seeing it on every newspaper front page? There are other things we could share you know, but we hate to embarrass a friend. Have a nice day Comrade Trump."