Facebook profile pic depicts ur age.
When u r young, school going, ur profile pic includes all the superheroes, spiderman, superman; movie actors, shahrukh, salman, or some other guy u admire.
When u r nearing ur 8th or 10th grade, ure photos mostly include group photos with ur group of chaddi buddy friends.
When u just enter college, the pics include, the nicely dressed up and new u, desperate enough to make impression among new gals in college, partying, with guitar.
This phase might be followed by pics intermittently with ur new found gfs, or u wasted with all the booze.
Then comes the phase when u start working, flaunting the money u make with visits to all expensive clubs and restaurants. And also to different country. And again intermittently ur wasted pics with booze.
Now when ure reaching a age of 25-29, ure again desperate, u again wanna impress all the female folks, so u put up all sexy pics, strutting ur stuff.
Now as ure getting a little old, u realize, ure getting ugly too, so u put up pics of ur childhood, to hear all ur female friends comment, "so cute", " so sweet"
Then out of no where, u actually find a gal n get married, profile pic is with ur newly wedded wife, yes that includes pics taken everywhere u visit.
OK once u get married, then u have kids, now ur profile pic is with ur wife and kid, or only ur kid.
Then comes a phase when ure into a self made exile from facebook for many years, called "Facebook is for kids"
Then when u actually get old, u start putting all spiritual pics of gods and temples as ur profile pic.
Disclaimer: This is just a generalization of things i see on facebook written on a humorous note, not to hurt anyone's sentiments.