True, all leg bones appear to be round, but most of the best Show Calves are flatter boned, making them look also more heavier boned. The rounder boned heifer calves presents another decision on breeding. A Judge is looking for angles, not curves in both Steers and Breeding Stock. A "round boned" calf will carry the same characteristics right through the rump, hip, ribs, and shoulders. Breeding to Heavy, Flat Boned Bulls will produce flatter boned calves down the generations.
In your case, clipping tighter translates to less hair on the outsite and inside of the legs, but more in front and back. The rump will need to be very tight to the point it begins to round, and then leave as much hair as possible to the edges. Clipping the top line, you will make the calf appear wider and flatter by clipping very close right down the middle, and pulling more hair upward on the sides. You want to see a straight line across the back when viewing from the side. You will also need to leave a little more hair in front of and behind the shoulder, while clipping very closely right at the shoulder.
ANGLES AND STRAIGHT LINES ARE ALL YOU WANT TO SEE! Eliminate the curves with hair and clipping, and even a round boned calf can be a winner. Hope you remember your Geometry.
