I believe we are all jumping to conclusions. Do we know its company policy for people to watch that stuff or is it the individuals doing so in order to get inspired. The person said they would walk by seeing people watching this stuff but that just might only be for people who need to do so because for some reason they believe it will help them with making the game.
It would be different if we read that people are being forced to watch such content in order to do their job and if they did not they would be fired or something along those lines.
I would suggest it should be company policy not to expose your co-workers to such graphic images and that the company holds some responsibility for allowing such an environment.