Yes, but the word 'designed' only goes as far as the housing.
It's one of those marketing miracles, selling the 58 for more money.
and SM58 are essentially the same, except that the SM57
was intended mainly for instruments and the SM58 for vocals. The SM58 has a ball grille that acts as a pop filter. The two mics have the same proximity effect at the same miking distance.
Because of its smaller grille, the SM57 lets you get closer to it for more bass boost. But if you are 2 inches from the diaphragm in either mic, they have the same bass boost.
They have a slightly different response at high frequencies because of the acoustical effects of the different grilles"
So ... take the ball grille off both of them, and they are the same ...
Read the full discussion, complete with brainwashed 'opinions' here ...