Besides simply being astonishingly handsome men, Brad and Bob are look-alikes. There's a subtle similarity that may not hit you over the head, but can be seen all over their faces. The foreheads are equally high and square, with a similar hairline. Their eyebrows are alike in their straight heaviness.
And their eyes -- see how they both have a sort of squintiness to their lower lids. Sure, the noses are a bit different, but they both have the same a strong square jaw with barely there dimples and a similar shape to the mouth and teeth.
Way to go guys. You know just how to be gorgeous!