The models (apart from the tank) shouldn't have snow on them, but the bases look fantastic. When the marines move, they will shake off the snow.
A Thousand Suns marine who was standing guard would probably end up looking like that though, since they have no body heat to speak of
As for the camera, brace your hands on the table to minimise shake. Set it to "Macro" (looks like a little flower symbol), and set it to a couple second of delay on the timer. (probably a clock symbol). Or, if it's got the functionality, you should be able to set it to AUTO and it'll take decent looking pictures, at least, by itself. Never, ever, use flash on miniatures.