What "art quilt" means is obviously open to interpretation. I think of true art quilting to be having a vision and going for it, with or without pattern, or instructions. Usually there will be a definite technique (like making an image by thread only-- there have been lots of pets done this way, and pictures of a woman presented more than once here on QB), or it can be totally fabric, but done as a landscape or an abstract, or ......? with or without embellishments.
There is an art quilt thread going on now, and I followed it for a while, but I'm not "into" embellishments or dark concepts (dark gray quilts depress me) and I was hoping they might start having specific technique, or concept threads, but that became a controversary. I'd like to see a thread that is basically "landscape", and another basically "portraits" (people, and animals), but I can't start it because I can't upload onto QB.
PatriceJ has put pictures up into categories and there are about 30 photos of quilts that QB members themselves consider to be "art quilts". They are a wonderful example of what I was trying to say above. Made from the heart, not just from a pattern.