In this photo, Foreign Minister Lavrov is smiling, even laughing. The Russians have now (temporarily) headed off (explicit) US intervention against the Russian/Iranian puppet.
But the US is allegedly supplying arms to the rebels via the CIA. From a broad perspective, the US is likely hoping for a lengthy stalemate between two anti-US factions in many respects.
At the same time if the rebels are more pro-western (is that possible?), say like the rulers of Saudia Arabia or UAE, then supporting the rebels would eventually undercut the Russian natural gas monopoly over Europe and might very well be a good strategy. But to do that, they US must support the right rebels (assuming that is possible and such a group even exists).
But it looks like a short-term Russian diplomatic victory. No wonder Lavrov is laughing and Kerry appears to be grimacing.