This is Vyborg's Gulf which was just frozen a few days ago. Two lines on backplane are the channels, made by icebreaker, one to Vyborg's harbour, another to Saima channel. Two people on bykes and two walkers looks quite funny in this environment.
Yes, these are two buoys to mark the sides of the far channel for ships. The far channel is a path from Vyborg's Gulf to the Saima channel, the chain of lakes connected with artificial channels. It gives a way to the sea for the inner parts of Finland.