Okay, I might be avoiding the topic at hand as far as the effort by the X to stir the pot. However, I will say that putting up pics of the X in the child's room is NOT sick. Perhaps the selection of which one to put up is a calculated thing which sends the wrong message.
One of the things I learned in an orientation class for the county to conduct a social study is that when they do a home visit, they will actually LOOK to see if the child has pics of the other parent in his/her room. The non-present parent is STILL the child's parent, and someone for the child to love/remember/cherish during separation/divorce. Not encouraging that relationship, at least in the context of a social study, is considered a negative. Don't ask me how, but it shows a non-willingness to co-parent.
One of the three pics in the daughter's room at my home is a family pic - not because I want to give her some kind of false hope, but because it's a lovely pic of the three of us. My hopes are that she realizes that I do NOT have an issue with him in the context of parenting. I would hope that someday, during an event where she should be proud of herself (as was the case in the pic I selected) that we can all three be in a picture together to celebrate her accomplishment.