It's a character turnaround from the mighty Jose-Luis Garcia-Lopez and Dick Giordano, used so that anyone who needed to draw Batman, or a company which wanted to use Batman on their merchandise (and had paid for the rights) would have a model to work from. In many cases they just used the art supplied, which is stellar! It's said, and plausibly so, that many an artist did freelance work with DC just so they could get the Style Guide which is pages and pages of the same level of artwork on ALL the major DC characters.

These samples were scanned from a calendar released in the UK a few years ago, and here are a few more (Others include Joker, Riddler and Penguin)

As someone commented on seeing these, they even nailed the personalities in the poses they take up;

Batman finds one that works and stays with it.

Batgirl has a sort of "Okay, I'll turn around for you, but I have better things to do than stand here for you"

Whereas Robin, natural showman and acrobat that he is is "Sure I can stand like this, or like this, oh, you want a rear view, no problem... would you like me to wiggle anything perhaps? Y'know, this is FUN!"