One of the grating issues between art and decoration is the ability to fade into the background, to hang nicely on the wall without interfering. Portraits often break this deal. You can see this in many films, where portraits of ancestors appear to play a part of the drama. They look down ominously on the participants and seek to remind them of the way they did things until camera and conversation finally acknowledge them. That's one of the tasks of art. It adds meaning to your life, whether you want it or not.