Can be many things, a popover, but surely they must always pop over the head (hence the name) and be alike in concept and function to a shirt. This one has an open, one-piece collar, as well as a fairly long, relaxed body, so that it may function as a useful mid-layer — over a shirt, even — from time to time.
The popover is open at the front, halfway down the chest, but it can be fastened, for the more conservative amongst us, with the help of a button halfway down, to gently cajole the two sides of the front together. Accordingly, the collar is softly pressed, so rolls out elegantly, rather than with a fixed break.
The popover has short sleeves, which end just above the elbow on mannequins of typical proportions.
The hem on the body is straight all the way around. There's a yoke across the upper back, into which is built a hanging loop. Lower down, meanwhile, are vents built into the side seams, which, while only a couple of inches high, increase by miles and miles the ease with which it can be lifted over a head.
This is a high-count weave of long-staple linen yarn, most notable maybe for having been given the proverbial once-over in a specialised washing and tumbling process at the mill. It has a dry hand, a rumpled texture akin to freshly laundered laundry, and floats breezily away from the skin.