Greetings Igut,
As much as Mare would like to honor all requests, she can't possibility answer and address everything student put out there.
Whether or not Marie Diamond saying something is disturbing would make any impact on your son, is not very likely. What you can do is ask him what people coming into the room and seeing the poster would think it portrays in intent and emotion. If a person openly looks at a photo and describes what is shown, chances are it will be fairly obvious if it is a supportive and representative of who they want to be in the world or not.
What would also be interesting is to muscle check him by using his name/not his name as the control, then have him hold his hand by his heart and test, followed by holding the poster by his heart and testing.
Much Love,
Shawn