He's looking at this thinking (even if he doesn't say it out loud) "Murray sucks, I can easily win this starting job." Murray no doubt thinks the opposite.Clearly Samsonov is okay with it if he signed.
I've been in these situations in juniors. Both as a de-facto starter and as the supportive backup and life was good. We all knew our roles. When the other goalie and I didn't know our place it was mental hell on both of us