What is the significance of the artwork (that shows a woman lying in a field reaching/looking across a field of grain toward a farmhouse--the implication, perhaps, is a painting of Julia Harper)? Is that particular piece of art a familiar work already in existence? (For me, it was either a case of deja vu or I actually saw the picture from that scene within a week prior to seeing the movie.)
The Painting is Christina's World by the American painter Andrew Wyeth.
I think it is supposed to be one of the works of art saved by the survivors, Why Julia had it at the end (I think Jack put it in her sleep capsule, but can't recall 100%) is that Julia said it reminded her of home.