The American attitudes about what's safe for work are mostly shaped by sexual harassment law. It's not that our employers believe Porn Is Evil; it's that they

The American attitudes about what's safe for work are mostly shaped by sexual harassment law. It's not that our employers believe Porn Is Evil; it's that they fear being sued. It's not even that the courts believe Porn Is Evil; it's that showing an employee porn is one of the tactics of managers who want to have sex with their employees. Since forcing your employee to have sex with you is definitely slimy, we all go along with the NSFW stuff as a necessary cost of reducing slime in the workplace. But it does mean that we can wind up with a case where nobody in a group would object to a picture personally, but nobody in that group can be allowed to show it to anyone else in the group.