The glare is washes out a lot of detail in this photo, and the watch kinda crooked. I'd try using artificial light and try very hard to line the watch perfectly square with the camera, and zoom in enough to lose the knob or out enough to capture the whole thing. :)
It might be just me, but circles don't make me think "curves". To me, a curve is an open-ended, continuous unbounded thing. Technically, this has to have been a tricky shot; use of macro is good, but the lighting glares on the watch case, hiding some of the detail.
Nice detail. The flash spots are a bit distracting. I'd try to take this picture with more ambient lighting and no flash. If you can extend your shutter speed (and have a tripod or means of steadying your camera) you could do this under normal lighting
I like the subject of your photograph. The light glare near the watch dial is a bit too strong. The photo is a little grainy as well... maybe comes from cropping this segment from a much larger original photograph...