Disclaimer: I have never (at least) yet made a report, but these were the ones i came up from thinking many good reports i've read here.
Pictures i would be use: the ones that noone has seen before, like wonder movie intros, era splashes etc of course !
Ok, for real..
1. Overview of the empire after its first/second city and the scouted area, some periodical checks of empire(s) growth. Relations, statistics and graphs that give out info about your empire's state and development.
2. Possible attack plans etc, big stacks, wonderful (own, enemy) cities, resource clumbs.. the prizes!
3. Other interesting/funny things, wierd formations, barbs blocked eternally behind that mountain, whatever you find funny and would like to read from report yourself.
Just meaning info/lesser info/other interest stuff would be my preferred order, depending how long the game was and how long the report will be.