This is not the one I saw in Bolton but is the same sort of thing, from Milford, MA. It is an armchair near a rock pile site. I think it is clear that someone went to a bit of bother to get an armchair out in the woods. Maybe a grandpa wanting to be comfortable got his teenage grandsons to help carry the chair out there. Also it hints that this is a place to sit even if you do not have an armchair.