Think about pottery. Clearly some pottery is made to be, and achieves, "fine art" status. But other pottery is just coffee cups in a rack.
No one argues that pottery isn't both utilitarian and a medium for art.
Someone brought up the medium point pages back. Clearly snapshots at a family gathering don't work their way up to art just because you have them in a scrapbook. Just as clearly images designed to evoke a response and staged appropriately are more than the memory jogging memento under grandmother's coffee table.
In my mind the art/memento dichotomy is determined by intent.
I'll stay out of the "fine" fray. That is fraught with hyperbole.