The 0.45m mark equals 17 inch. That's 17 inch from the film plane, or in this case the sensor. The missing 5 inch could be from the front of the lens to the film plane. A 12 inch close focus distance would equate to a 0.30m setting on the lens barrel. Most standard 50mm SLR lenses go to something like .45 meters..
Nice cat photos by the way, but then I'm biased of course as I'm very fond of cats..