Watchtower with American Flag, Poignant Old Real Photo Postcard

I tend to look at everything these days as metaphors, and certainly do this one--a watchtower with windows on all sides (one might think of it as a surveillance station) flying an American flag. So it seems these days. And yet, the masking of the photo, creating the wide, soft cornered frame around the image, makes it seem as if the watchtower itself was glimpsed through some sort of window or scope and thus reverses the order of things: the surveilled in fact surveilling the watch tower! 

5 7/16 x 3 3/8 and in very good condition, unused postcard back with some smudges.