It’s a new feature that flickr has added quite recently – it allows flickr users to “Add a Person” specifically – instead of simply adding a tag with the person’s name.
To see a list of “people” added in my photostream click on http://www.flickr.com/photos/smriti/people/ and to see pix / images I have been added to as a Person click on http://www.flickr.com/people/smriti/photosof/
What most excites me about this particular feature – once I’m added to a pix (that is not mine), I have access to the pix even if it is not publicly available.
To add myself to a pix is really easy. All I have to do is be logged in as myself. Then as I find myself in a pix (no matter who owns the image), I simply click on the “Add a person” link to the right of the image (just above the tags).