There are so many uses for shelf brackets! These are shelf brackets, repurposed to frame a window --- what a clever idea. You could do this to define and separate spaces in the same room, too. (Say an entryway and a dining room.
It seems that each spring home owners are looking for new ways to spruce up their landscaping. Everyone likes to have a nice looking yard. There are many trends now to help people extend their living space into the outdoors.