Every actor knows they need different "looks" when they are going to get their headshots taken. But some get so caught up in what looks they need (or their agent or manage wants) that they forget about who they are themselves!
I'm not anti-looks by any means... I know that casting directors don't have a lot of time to do their job and need to see right away that you can fit the character, the type, and the show they are casting, so having a good, specific headshot is vital for being brought in. But we are all unique. When you get in that room, whether you book it or not is likely to have something to do with who you are as a person. Dozens of people will go in as a cop, a lawyer, or as waitress number two, but whoever books it will have done something differently to the rest as their cop/lawyer/waitress. Something unique to them.
So, just like you would in an audition, bring that cop, or lawyer, or waitress to your next headshot shoot. But don't forget to bring yourself, too.