I was sitting in on a call to discuss options for photography to go on a corporate website today. The pictures were typical people shots, you've seen these on thousands of sites. The main concern was that the people shown should be representative of the users.
The conversation was interesting - if you're interested in categorizing.
"Everyone looks under 30."
"Our managers don't wear suits, they're more business casual."
"It's not diverse enough, we have a lot of emphasis on diversity here."
"Some people thought it was inapropriate that the man and the woman were touching."
"I don't like the arms crossed like that, it's not very accessible."
"That's the right smile."
"That look is too suity."
"Our people don't wear turtlenecks."
"Last time we used real people from our company they all left within a year."
Bonus: Information Architecture exercise: try to create a taxonomy of people pictures for use on websites after reading these comments.